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An Intelligent Face Mask Integrated with High Density Conductive Nanowire Array for Directly Exhaled Coronavirus Aerosols Screening
Abstract
The current ongoing outbreak of Coronavirus Disease 2019 (COVID-19) has globally affected the lives of more than one hundred million people. RT-PCR based molecular test is recommended as the gold standard method for diagnosing current infections. However, transportation and processing of the clinical sample for detecting virus require an expert operator and long processing time. Testing device enables on-site virus detection could reduce the sample-to-answer time, which plays a central role in containing the pandemic. In this work, we proposed an intelligent face mask, where a flexible immunosensor based on high density conductive nanowire array, a miniaturized impedance circuit, and wireless communication units were embedded. The sub-100 nm size and the gap between the neighbored nanowires facilitate the locking of nanoscale virus particles by the nanowire arrays and greatly improve the detection efficiency. Such a point-of-care (POC) system was demonstrated for coronavirus ‘spike’ protein and whole virus aerosol detection in simulated human breath. Detection of viral concentration as low as 7 pfu/mL from the atomized sample of coronavirus aerosol mimic was achieved in only 5 mins. The POC systems can be readily applied for preliminary screening of coronavirus infections on-site and may help to understand the COVID-19 progression while a patient is under prescribed therapy.
... The large majority of reviewed papers utilized a three-electrode system [9,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65]. However, in EIS, because impedance is the main parameter, it is possible to operate with a two-electrode system [66][67][68][69]. In theory, two-electrode systems with a WE and a combination RE/CE are inherently less stable with repeated measurements than their three-electrode counterparts [17]. ...
... A dedicated CE is important for providing a low-resistance path for current to flow to (1) prevent signal attenuation due to the high-resistance RE and (2) protect the RE from high currents, which can damage it and its ability to establish a stable reference potential [17]. However, the two-electrode systems reviewed demonstrated limits of detection (LOD) comparable to the best of their three-electrode counterparts, reaching past the femtomolar and femtogram/milliliter ranges [66][67][68][69]. This impressive performance is likely due to extreme measurement ranges (Soares et al.), which can artificially improve LOD and the use of highly specific, small aptamers for binding (Ramanathan et al.) (the impact of these two factors will be discussed later) [66,67]. ...
... This impressive performance is likely due to extreme measurement ranges (Soares et al.), which can artificially improve LOD and the use of highly specific, small aptamers for binding (Ramanathan et al.) (the impact of these two factors will be discussed later) [66,67]. Of the four two-electrode papers, only Xue et al. measured repeatability within the same electrode, demonstrating an acceptable 4.7% (n = 3) relative standard deviation (RSD) ( Figure 5) [69]. ...
The COVID-19 pandemic revealed a pressing need for the development of sensitive and low-cost point-of-care sensors for disease diagnosis. The current standard of care for COVID-19 is quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). This method is sensitive, but takes time, effort, and requires specialized equipment and reagents to be performed correctly. This make it unsuitable for widespread, rapid testing and causes poor individual and policy decision-making. Rapid antigen tests (RATs) are a widely used alternative that provide results quickly but have low sensitivity and are prone to false negatives, particularly in cases with lower viral burden. Electrochemical sensors have shown much promise in filling this technology gap, and impedance spectroscopy specifically has exciting potential in rapid screening of COVID-19. Due to the data-rich nature of impedance measurements performed at different frequencies, this method lends itself to machine-leaning (ML) algorithms for further data processing. This review summarizes the current state of impedance spectroscopy-based point-of-care sensors for the detection of the SARS-CoV-2 virus. This article also suggests future directions to address the technology’s current limitations to move forward in this current pandemic and prepare for future outbreaks.
... In 2021, Qiannan Xue, et al. designed a smart mask with a high-density conductive nanowire array, which could be used for direct exhaled coronavirus aerosol screening. [237] Molecular detection based on the gold standard RT-PCR requires professional operators and a long processing time. The authors proposed a smart mask, embedded with flexible immune sensors based on high-density conductive nanowire arrays, miniaturized impedance circuits, wireless communications, and other devices, which could achieve the capture and removal of nanoscale virus particles from the mask in just 5 min. ...
... The application of this smart mask system is simple for the first screening of coronavirus infections in the field, and it could be useful in determining how a virus is progressing in patients who are following treatment recommendations. [237] In 2024, Wei Gao, et al. developed a wireless smart mask, in which exhaled breath condensate (EBC) offers valuable molecular insights into health. Introducing EBCare, a mask-based device for real-time EBC biomarker monitoring, which employs a tandem cooling strategy, automated microfluidics, selective electrochemical biosensors, and wireless circuitry. ...
Air pollution is a silent killer. It poses a significant health threat, affecting over 80% of the global population and leading to respiratory and cardiovascular diseases. Electrospun nanofiber filtration membranes have made tremendous progress due to their large surface areas, adaptable structures, and self‐polarizing properties. This review explores recent developments in nanofiber filtration membranes across four key areas: filtration principles, material design, structural innovations, and functionalities. Initially, classical filtration mechanisms is discussed, followed by an overview of sustainable materials and green technologies for advanced filtration. It is then delve into structural advancements, highlighting nanofibers with high roughness, ultra‐fine diameters, and bimodal distributions. Inspired by nature, these innovations have led to the creation of high‐performance filtration membranes. Current research focuses on anti‐bacterial and antiviral filtration membranes, as well as intelligent systems capable of sensing physiological signals. Last, the existing challenges in filtration membrane development, such as new filtration mechanisms, green preparation technologies, and reusable intelligent filtration systems is highlighted. It is anticipated that solutions to these problems will open up new possibilities for functional biodegradable membranes, smart wearables, and upscale healthcare.
... Such sensors may also generate read-out values that may provide information about the amount of analyte species that have been detected. These approaches also have recently been used in other respiratory equipment such as face masks and breath analysis systems [35][36][37][38][39] as shown in Figure 3. ...
... Reproduced (adapted) with permission from, [37] Copyright 2019 American Chemical Society; c) Impedance-based sensor with protein detector for sensing COVID-19 in human breath with Bluetooth and wireless connection. Reproduced (adapted) with permission from, [35] Copyright 2021 Elsevier; d) PVA-CNF based humidity sensor with real-time and wireless monitoring humidity of user for respiratory monitoring applications Image reproduced from, [36] Creative Commons 4.0; e) carbon nanotube composites on a face mask for selectively detecting of formaldehyde, ethanol, and ammonia with embedded signal processing and LED light indicators reproduced (adapted) with permission from, [39] Copyright 2021 Springer Nature. ...
Canister‐based air purification respirators are frontline personnel's first point of defense against airborne contaminants. Tremendous advancements in filtration and purification materials have occurred in recent years, particularly with the advent of multifunctional, high‐surface‐area materials. Despite these, a significant challenge remains for canisters, and that is knowing when, without a doubt, they should be replaced. Residual lifetime indicators (RLIs) are essential for informing wearers when to make an active decision to replace their canister. RLIs can also be used to inform policymakers of appropriate changeover schedules, thereby reducing the wearer's risk of becoming exposed to airborne contaminants. This paper discusses some of the challenges with current changeover approaches and examines key issues for incorporating RLIs into canister respirators. A variety of sensor technologies and methodologies are examined, along with some recent RLI developments in the research and patent literature. A discussion on the challenges for making RLIs more amenable for incorporation into canisters is provided, along with recommendations for future development.
... Next to commercial EBC collection systems such as the R-tube condensers, several engineered EBC-collection systems have been reported in the literature [16][17][18][19][20]. Wagner and co-workers recently proposed an innovative EBC collection device in which EBC is condensed inside stainless steel tubes with a collection efficiency of 500 µL min −1 [21]. ...
... Next to commercial EBC collection systems such as the R-tube condensers, several engineered EBC-collection systems have been reported in the literature [16][17][18][19][20]. Wagner and co-workers recently proposed an innovative EBC collection device in which EBC is condensed inside stainless steel tubes with a collection efficiency of 500 µL min −1 [21]. Several face mask-based EBC collection systems have been proposed in parallel since the start of the COVID-19 pandemic [19,20,22,23]. Duan et al. have previously demonstrated the effectiveness of using EBC as a probe for the detection of SARS-CoV-2 infections [24]. ...
In this study, we present a novel face mask engineered for the collection of exhaled breath condensate (EBC) and its application and performance in a clinical study of COVID-19 infection status assessment versus the gold standard polymerase chain reaction (PCR) nasopharyngeal swab testing. EBC was collected within a clinical trial of COVID-19-infected and non-infected patients and analyzed by reverse transcription quantitative (RT-q) PCR, with the results being compared with nasopharyngeal sampling of the same patient. The cycle threshold (Ct) values of the nasopharyngeal samples were generally lower than those of EBC, with viral loads in EBC ranging from 1.2 × 104 to 5 × 108 viral particles mL−1 with 5 min of breathing. From the 60 clinical patients’ samples collected, 30 showed a confirmed SARS-CoV-2 infection. Of these 30 individuals, 22 (73%) had Ct values < 40 (representing the threshold for SARS-CoV-2 infectivity) using both amplification of ORF1a/b and the E-gene. The 30 EBC samples from non-infected participants were all identified as negative, indicating a 100% specificity. These first results encourage the use of the face mask as a noninvasive sampling method for patients with lung-related diseases, especially with a view to equipping the face mask with miniaturized sensing devices, representing a true point-of-care solution in the future.
... The best method, which has been employed to investigate the link between breath volatility and lung cancer, appears to be the use of sterile bags. Since the pandemic epidemic demonstrated that both asymptomatic and presymptomatic people might spread influenza, any breath analyzer that collects samples should have filters [47]. Using sensors built into the face masks provides a flexible substitute for a breath analyzer. ...
... Using sensors built into the face masks provides a flexible substitute for a breath analyzer. Cellulose, which has been researched as a substrate for flexible wearable and paper-based sensors, makes up the majority of masks [46][47][48]. The blood gathers the volatile molecules from numerous organs and tissues, and at the blood/air interface in the lungs, they are transported to breathe. ...
... Copyright 2021, Springer Nature); (b) A mask-based diagnostic platform for point-of-care screening of COVID-19 (Reprinted with permission from Ref. [141]. Copyright 2021, Elsevier B.V.); (c) An intelligent face mask integrated with a high-density conductive nanowire array for directly exhaled coronavirus aerosol screening (Reprinted with permission from Ref. [142]. Copyright 2021, Elsevier B.V.). ...
... Xue et al. also reported a direct exhaled coronavirus aerosol screening face mask using anti-spike proteins of SARS-CoV-2 [142]. The sensor consists of three layers: a droplet collecting protective outer layer of polycarbonate membrane, sensing bio-functional middle layer, and a PET supportive substrate to adhere to on the mask (Figure 6c). ...
A mask serves as a simple external barrier that protects humans from infectious particles from poor air conditions in the surrounding environment. As an important personal protective equipment (PPE) to protect our respiratory system, masks are able not only to filter pathogens and dust particles but also to sense, reflect or even respond to environmental conditions. This smartness is of particular interest among academia and industries due to its potential in disease detection, health monitoring and caring aspects. In this review, we provide an overlook of the current air filtration strategies used in masks, from structural designs to integrated functional modules that empower the mask’s ability to sense and transfer physiological or environmental information to become smart. Specifically, we discussed recent developments in masks designed to detect macroscopic physiological signals from the wearer and mask-based disease diagnoses, such as COVID-19. Further, we propose the concept of next-generation smart masks and the requirements from material selection and function design perspectives that enable masks to interact and play crucial roles in health-caring wearables.
... (D) Schematic illustration of a nanoscale sensor design and virus sensing mechanism. Reproduced with permission from Ref. [54]. (E) Schematic of elution of the virus from the wearable collector with antibody-based sensing. ...
... The immunological binding for each technique is on a paper strip, on a metal surface at the interface of a glass and liquid media, and on a surface of a well plate, resulting in color, fluorescence, and electrical signals ( Fig. 2D and E). Their outstanding features of quick response, miniature size, low cost, and easy integration have contributed to the development of rapid on-site bioaerosol collection and detection technologies [43,54]. The disadvantages of immunological assays are possible falsepositive results, complex measurement steps, and environmentally sensitive components. ...
As the recent coronavirus disease (COVID-19) pandemic and several severe illnesses such as Middle East respiratory syndrome coronavirus (MERS-CoV), Influenza A virus (IAV) flu, and severe acute respiratory syndrome (SARS) have been found to be airborne, the importance of monitoring bioaerosols for the control and prevention of airborne epidemic diseases outbreaks is increasing. However, current aerosol collection and detection technologies may be limited to on-field use for real-time monitoring because of the relatively low concentrations of targeted bioaerosols in air samples. Microfluidic devices have been used as lab-on-a-chip platforms and exhibit outstanding capabilities in airborne particulate collection, sample processing, and target molecule analysis, thereby highlighting their potential for on-site bioaerosol monitoring. This review discusses the measurement of airborne microorganisms from air samples, including sources and transmission of bioaerosols, sampling strategies, and analytical methodologies. Recent advancements in microfluidic platforms have focused on bioaerosol sample preparation strategies, such as sorting, concentrating, and extracting, as well as rapid and field-deployable detection methods for analytes on microfluidic chips. Furthermore, we discuss an integrated platform for on-site bioaerosol analyses. We believe that our review significantly contributes to the literature as it assists in bridging the knowledge gaps in bioaerosol monitoring using microfluidic platforms.
... As shown in Figure 5A, Xue et al. [117] proposed an intelligent face mask, which enables on-site virus detection. This intelligent face mask consists of three layers. ...
Flexible electronic devices with compliant mechanical deformability and electrical reliability have been a focal point of research over the past decade, particularly in the fields of wearable devices, brain–computer interfaces (BCIs), and electronic skins. These emerging applications impose stringent requirements on flexible sensors, necessitating not only their ability to withstand dynamic strains and conform to irregular surfaces but also to ensure long‐term stable monitoring. To meet these demands, one‐dimensional nanowires, with high aspect ratios, large surface‐to‐volume ratios, and programmable geometric engineering, are widely regarded as ideal candidates for constructing high‐performance flexible sensors. Various innovative assembly techniques have enabled the effective integration of these nanowires with flexible substrates. More excitingly, semiconductor nanowires, prepared through low‐cost and efficient catalytic growth methods, have been successfully employed in the fabrication of highly flexible and stretchable nanoprobes for intracellular sensing. Additionally, nanowire arrays can be deployed on the cerebral cortex to record and analyze neural activity, opening new avenues for the treatment of neurological disorders. This review systematically examines recent advancements in nanowire‐based flexible sensing technologies applied to wearable electronics, BCIs, and electronic skins, highlighting key design principles, operational mechanisms, and technological milestones achieved through growth, assembly, and transfer processes. These developments collectively advance high‐performance health monitoring, deepen our understanding of neural activities, and facilitate the creation of novel, flexible, and stretchable electronic skins. Finally, we also present a summary and perspectives on the current challenges and future opportunities for nanowire‐based flexible sensors.
... Triggered by a simple button press, the device operated autonomously, maintaining high sensitivity and specificity without requiring power or liquid handling. In addition, an impedance-based breath pathogen sensor was proposed to detect respiratory viruses, including the SARS-CoV-2 spike protein (Fig. 2h) 57 . Hydrophilic porous membrane efficiently collected droplets, and anti-spike functionalized nanowire arrays effectively captured the targeted viral proteins, resulting in detectable changes in impedance. ...
Within the breath lie numerous health indicators, encompassing respiratory patterns and biomarkers extending beyond respiratory conditions to cardiovascular health. Recently, the emergence of the SARS-CoV-2 pandemic has not only underscored the necessity of on-the-spot breath analysis but has also normalized the use of masks in everyday life. Simultaneously, the rapid evolution of wearable technology has given rise to innovative healthcare monitoring tools, with a specific emphasis on wearable breath sensors. This review explores current research trends in utilizing wearable breathing sensors to detect diverse respiratory biomarkers and monitor respiratory parameters, including airflow, temperature, and humidity. Additionally, it explores diverse applications, ranging from recognizing breathing patterns to swiftly detecting diseases. Integrating the Internet of Things and machine learning technologies into these applications highlights their potential to offer a personalized, accurate, and efficient healthcare solution.
... Additionally, the companies Deep Sensing Algorithms (DSA; Finland) and Imspex Diagnostics (UK) received CE-marking for their spectroscopic-based breath tests to determine a person's metabolic response to COVID-19 [26,27]; however, their real-world effectiveness and applicability remain to be seen. Moreover, although still in the preclinical stages, exhaled breath aerosol (XBA) collection paired with SARS-CoV-2 molecular detection is showing promise [28][29][30][31]. Unlike VOCs, direct nucleic acid or antigen-based pathogen detection in XBA has the potential to be highly specific and is associated with the transmission of respiratory pathogens. ...
The COVID-19 pandemic brought diagnostics into the spotlight in an unprecedented way not only for case management but also for population health, surveillance, and monitoring. The industry saw notable levels of investment and accelerated research which sparked a wave of innovation. Simple non-invasive sampling methods such as nasal swabs have become widely used in settings ranging from tertiary hospitals to the community. Self-testing has also been adopted as standard practice using not only conventional lateral flow tests but novel and affordable point-of-care molecular diagnostics. The use of new technologies, including artificial intelligence-based diagnostics, have rapidly expanded in the clinical setting. The capacity for next-generation sequencing and acceptance of digital health has significantly increased. However, 4 years after the pandemic started, the market for SARS-CoV-2 tests is saturated, and developers may benefit from leveraging their innovations for other diseases; tuberculosis (TB) is a worthwhile portfolio expansion for diagnostics developers given the extremely high disease burden, supportive environment from not-for-profit initiatives and governments, and the urgent need to overcome the long-standing dearth of innovation in the TB diagnostics field. In exchange, the current challenges in TB detection may be resolved by adopting enhanced swab-based molecular methods, instrument-based, higher sensitivity antigen detection technologies, and/or artificial intelligence-based digital health technologies developed for COVID-19. The aim of this article is to review how such innovative approaches for COVID-19 diagnosis can be applied to TB to have a comparable impact.
... If superspreading individuals or events can be systematically identified, control efforts may reasonably focus on mitigating transmission in a more targeted manner [7]. This necessitates a high-performance digital surveillance system complementing mobile and wearable mask sample collectors, referred to as the masklect (for this purpose, we collected and tested SARS-CoV-2 RNA on surgical masks worn by COVID-19-infected patients from China; part 1 in Multimedia Appendix 1) [4,5,[8][9][10][11][12][13][14][15][16][17][18][19][20]. According to our previous reports [8], it is feasible to use GPS and geospatial artificial intelligence (AI) technology from smartphones to collect personal spatiotemporal trajectory data to construct the epidemic prevention strategy-STRONG (Spatiotemporal Reporting Over Network and GPS) [8]. ...
Lockdowns and border closures due to Coronavirus Disease 2019 (COVID-19) imposed mental, social, and financial hardships in many societies. Living with the virus and resuming normal life are increasingly being advocated with decreasing virus severity and widespread vaccine coverage. However, current trends indicate a continued absence of effective contingency plans to stop the next more virulent variant of the pandemic. The COVID-19-related mask waste crisis has also caused serious environmental problems and virus spreads. It is timely and important to consider how to precisely implement surveillance for dynamic clearance and how to efficiently manage discarded masks to minimize disease transmission and environmental hazards. In this viewpoint paper, we sought to address this issue by proposing an appropriate strategy for intelligent surveillance of infected cases and centralized management of mask waste. Such an intelligent strategy consisting of masklect and voiceprint against COVID-19 based on the STRONG strategy, could enable the resumption of social activities and economic recovery and ensure a safe public health environment sustainably.
... This indicated that the PETx coating not only enabled virus capture, but also prevented nonspecific binding (NSB), which benefits from hydrophilic OEG integration. 41 To test the specificity of the anti-SP-CSFA particles, another virus mimic (ZsGreen), which does not contain S-protein, was applied together with the pseudovirus. Here, ZsGreen and pseudovirus were mixed in 1 mL PBS (10 5 tu mL −1 ) at a 1 : 1 ratio and then incubated with the anti-SP-CSFA particles. ...
Virus infections remain one of the principal causes of morbidity and mortality worldwide. The current gold standard approach for diagnosing pathogens requires access to reverse transcription-polymerase chain reaction (RT-PCR) technology. However, separation and enrichment of the targets from complex and diluted samples remains a major challenge. In this work, we proposed a micromotor-based sample preparation concept for the efficient separation and concentration of target viral particles before PCR. The micromotors are functionalized with antibodies with a 3D polymer linker and are capable of self-propulsion by the catalytic generation of oxygen bubbles for selective and positive virus enrichment. This strategy significantly improves the enrichment efficiency and recovery rate of virus (up to 80% at 104 tu mL-1 in a 1 mL volume within just 6 min) without external mixing equipment. The method allows the Ct value in regular PCR tests to appear 6-7 cycles earlier and a detection limit of 1 tu mL-1 for the target virus from swap samples. A point-of-need test kit is designed based on the micromotors which can be readily applied to pretreat a large volume of samples.
... This approach not only determines COVID contamination by a less invasive method than the swab technique but it can also evaluate potential hazards caused by exhalation from an infected individual. Xue et al. (2021) take this a step further by embedding a non-Faradic impedance biosensor into the mask that detects virus particles using specific antibody-antigen immuno-interactions. Elias-Kirma et al. (2020) propose a microfluidic "lung-on -a-chip" that mimics aerosol travel through the respiratory tract using on-chip microfluidic analysis to evaluate bioaerosol exposures. ...
... The latest clinical studies have demonstrated that the breath emission rate of SARS-CoV-2 from infected patients [7] reaches an output of from one thousand to one hundred thousand copies [8] per min in a facemask [9]. To detect viruses, researchers have designed sensitive electrochemical biosensors [10,11] that use impedance change, before versus after viruses exposure, as the output signal [12]. However, the ultralow concentration of SARS-CoV-2 failed to be detected in real-time due to the non-amplified signals and limitations of the detection of the biosensors. ...
The effective control of infectious diseases, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, depends on the availability of rapid and accurate monitoring techniques. However, conventional SARS-CoV-2 detection technologies do not support continuous self-detection and may lead to cross-infection when utilized in medical institutions. In this study, we introduce a prototype of a mask biosensor designed for the long-term collection and self-detection of SARS-CoV-2. The biosensor utilizes the average resonance Rayleigh scattering intensity of Au nanocluster-aptamers. The inter-mask surface serves as a medium for the long-term collection and concentration enhancement of SARS-CoV-2, while the heterogeneous-nucleation nanoclusters (NCs) contribute to the exceptional stability of Au NCs for up to 48 h, facilitated by the adhesion of Ti NCs. Additionally, the biosensors based on Au NC-aptamers exhibited high sensitivity for up to 1 h. Moreover, through the implementation of a support vector machine classifier, a significant number of point signals can be collected and differentiated, leading to improved biosensor accuracy. These biosensors offer a complementary wearable device-based method for diagnosing SARS-CoV-2, with a limit of detection of 103 copies. Given their flexibility, the proposed biosensors possess tremendous potential for the continuous collection and sensitive self-detection of SARS-CoV-2 variants and other infectious pathogens.
... Intelligent wearable masks with additional functions can not only expand the application scope and scenario of masks but also reduce the use of disposable masks to a certain extent, thereby reducing environmental pollution. In addition, since the COVID-19 pandemic, researchers in the field have reported intelligent wearable masks as a component of personal protective equipment (PPE) primarily at the technical and functional level, including health monitoring [24][25][26], sensing viruses [27,28], infection notification [29], and self-powering [30,31]. It is rarely investigated at the level of product design. ...
Intelligent wearable masks are gaining increasing interest due to COVID-19 and the problems and limitations of existing masks. This paper prioritizes the design elements of personal protective equipment-intelligent wearable masks from the perspective of the product design domain. Using principal component analysis (PCA), the principal components of the design elements were selected first in this paper. Using the combined weights (PCA-AHP) method, the intelligent wearable masks’ prioritized design elements at each level were determined. The highest priority among the primary elements is comfort (0.3422), with the adjustable ear strap (0.1870) receiving the highest priority among the primary elements of comfort. The highest priority in functionality (0.2733) is anti-respiratory droplets/air purification (0.1097), the highest priority in usability (0.1686) is the easy removal and replacement of filters (0.0761), the highest priority in the aesthetic design (0.1192) is styling (0.0509), and the highest priority in material (0.0967) is flexible fabric material (0.0355). Finally, the six prioritized design elements were evaluated using fuzzy comprehensive evaluation (FCE), and overall, 76% of the experts considered them “appropriate” or “very appropriate” and 18% considered them “fair.” Therefore, this study’s six most prioritized design elements proposed for intelligent wearable masks can satisfy users’ needs.
... The SARS-CoV-2 pandemic had a positive impact in this field via the proposition of alternative breath collection approaches often mask-based systems [19][20][21], and the consideration of compiling with portable biosensors for immediate analysis, eliminating many of the confounding variables introduced by breath collection and sample storage [19][20][21][22][23][24][25]. The approaches are different from those of bioelectronic noses, and intelligent sensor arrays used to identify gases and vapors [26]. ...
Since the SARS-CoV-2 pandemic, the potential of exhaled breath (EB) to provide valuable information and insight into the health status of a person has been revisited. Mass spectrometry (MS) has gained increasing attention as a powerful analytical tool for clinical diagnostics of exhaled breath aerosols (EBA) and exhaled breath condensates (EBC) due to its high sensitivity and specificity. Although MS will continue to play an important role in biomarker discovery in EB, its use in clinical setting is rather limited. EB analysis is moving toward online sampling with portable, room temperature operable, and inexpensive point-of-care devices capable of real-time measurements. This transition is happening due to the availability of highly performing biosensors and the use of wearable EB collection tools, mostly in the form of face masks. This feature article will outline the last developments in the field, notably the novel ways of EBA and EBC collection and the analytical aspects of the collected samples. The inherit non-invasive character of the sample collection approach might open new doors for efficient ways for a fast, non-invasive, and better diagnosis.
... To improve PM 2.5 filtration efficiency, Au@SnO 2 nanoparticles were coated on the conductive fabrics. 35 The nanoparticles (5 mg) were first dispersed in a solution comprising 1 mL of IPA and 50 μL of Nafion. The conductive fabric was trimmed into a rectangle 2.5 cm in width and 2.5 cm in length. ...
In this work, we develop a wireless sensor-integrated face mask using Au@SnO2 nanoparticle-modified conductive fibers based on augmented reality (AR) technology. AR technology enables the overlay of real objects and environments with virtual 3D objects and allows virtual interactions with real objects to create desired meanings. With the help of the AR system, the size of the mask could be precisely estimated and then manufactured using 3D printing technology. The body temperature sensor and respiratory sensor were integrated into the mask so that vital parameters of the human body could be continuously monitored without removing the personal protective equipment. Furthermore, the outer part of the mask consists of conductive fabric modified with Au@SnO2 core-shell nanoparticle additives, which enhanced the filtration efficiency of airborne aerosols. A significant improvement in the filtration efficiency of particulate matter 2.5 was observed after applying an external voltage to the conductive textiles. A smartwatch with a heart rate sensor was paired with the mask to display sensor data on the mask through wireless transmission. Therefore, this sensor-integrated mask system with AR technology provides the first line of defense to combat global threats from pathogens and air pollutants.
... To further enhance the wearability of biochemical sensing devices, an intelligent face mask was developed to detect the coronavirus spike protein and whole virus aerosol. 100 This point-of-care system consists of a sub-100 nm nanowire array-based immunosensor for targeted viral particle capture, a miniaturized circuit for impedance measurement, and a Bluetooth module for result transmission. This system successfully demonstrated viral detection with a low concentration of 7 pfu/ml in only 5 min, convincing its potential for COVID-19 screening as well as disease spread mitigation. ...
Since its outbreak in 2019, COVID‐19 becomes a pandemic, severely burdening the public healthcare systems and causing an economic burden. Thus, societies around the world are prioritizing a return to normal. However, fighting the recession could rekindle the pandemic owing to the lightning‐fast transmission rate of SARS‐CoV‐2. Furthermore, many of those who are infected remain asymptomatic for several days, leading to the increased possibility of unintended transmission of the virus. Thus, developing rigorous and universal testing technologies to continuously detect COVID‐19 for entire populations remains a critical challenge that needs to be overcome. Wearable respiratory sensors can monitor biomechanical signals such as the abnormities in respiratory rate and cough frequency caused by COVID‐19, as well as biochemical signals such as viral biomarkers from exhaled breaths. The point‐of‐care system enabled by advanced respiratory sensors is expected to promote better control of the pandemic by providing an accessible, continuous, widespread, noninvasive, and reliable solution for COVID‐19 diagnosis, monitoring, and management. Wearable respiratory sensors can monitor biomechanical signals such as the abnormities in respiratory rate and cough frequency caused by COVID‐19, as well as biochemical signals such as virus biomarkers from exhaled breaths. The point‐of‐care system enabled by advanced wearable respiratory sensors is expected to promote better control of the pandemic by providing an accessible, continuous, widespread, noninvasive, and reliable solution for COVID‐19 diagnosis, monitoring, and management.
... Unlike nose swabs, breath sampling does not generate highly infectious contaminants and may be done nearly anywhere at any time. Recently, Qiannan et al. (Xue et al. 2021) proposed an integrated facial mask sensor that enables controlled diagnosis by aerosol and can easily detect coronavirus particle aerosols. However, the authors incorporated the nanobiosensor in a real face mask for the identification of a spiked solution of the S protein and evaluated the efficiency of the sample. ...
Contamination of water is a burning issue of modern civilization, and the issue has been an ever-increasing concern in the present global situation. The accessibility of fresh water has been constantly diminishing in recent years although the necessity of water, especially in the dry and semi-dry climate, is growing. This associated with territory exhaustion causes scarcity of water and results in declining oceanic biodiversity. Monitoring contaminants in wastewater spillovers has rendered imperative, and it has been crucial to recognize regions of water contamination and take appropriate measures for remedial action. The development of material science and nanotechnology, particularly the innovation of biosensors based on nanomaterials, has paved the way to detect bioanalytes with very high sensitivity, lower detection limit, and improved selectivity replacing the conventional methods and strategies, which more often suffer from poorer sensitivity and consumption of time. The rapid expansion of nanomaterials-based biosensing devices has generated a surge of interest due to their high affectability, selectivity, dependability, simplicity, low cost, and consistent response. This chapter gives a general overview of the development of recent nanobiosensors, focusing on their use in wastewater management.
... Unlike nose swabs, breath sampling does not generate highly infectious contaminants and may be done nearly anywhere at any time. Recently, Qiannan et al. (Xue et al. 2021) proposed an integrated facial mask sensor that enables controlled diagnosis by aerosol and can easily detect coronavirus particle aerosols. However, the authors incorporated the nanobiosensor in a real face mask for the identification of a spiked solution of the S protein and evaluated the efficiency of the sample. ...
Pollutants have become the global concern for which there is an intense demand for a quick, reliable, and sustainable system for their determination in the environment and agricultural land. Quantitative analytical tools such as chromatography and spectroscopy, albeit precise and accurate, expensive, requires experienced technician, complicated sample preparation steps, and difficult to assess at high frequencies in real-time. To overcome the issues, nanoparticle-based biosensors are considered as a potential tool to detect both biotic and abiotic toxins. With headways in nanotechnology, numerous specialists have utilized the one-of-a-kind properties of nanomaterials (counting a high surface-area-to-volume proportion) to foster efficiency and sensitivity in detection techniques. Nanomaterials have enabled us to design devices at the microscale level, prompting fast, versatile, and sensitive microorganism symptomatic frameworks that can recognize airborne microbes in clinics, air vents, and planes and bioterrorism in open spaces. Hence, this chapter gives an overview of the usage of nanobiosensors in the detection of contaminants. Further, the present scenario and future scope are also discussed in the development of novel detection devices, and their advantages over other environmental monitoring methodologies.
KeywordsBiosensorsNanoparticlesContaminantsPathogens
... Unlike nose swabs, breath sampling does not generate highly infectious contaminants and may be done nearly anywhere at any time. Recently, Qiannan et al. (Xue et al. 2021) proposed an integrated facial mask sensor that enables controlled diagnosis by aerosol and can easily detect coronavirus particle aerosols. However, the authors incorporated the nanobiosensor in a real face mask for the identification of a spiked solution of the S protein and evaluated the efficiency of the sample. ...
Nature contains technologies that will make our lives easier. Hundreds of examples of biomimetics are now found in our daily life, one of such is biosensors. Biosensors studies have been continuously developing in recent years. The increase and widespread use of these studies are due to the fact that biosensors give correct results in many application areas in a short time. Nanoparticle-based biosensors are preferred in environmental monitoring because they are very sensitive and fast. There are high levels of potential analyte in air, water, and soil. In addition to current pollution situations, they are potential uses for farming, horticulture, and mining nanobiosensors. Nanobiosensors can detect oil spills and radioactive contamination in groundwater, as well as the concentration of toxic wastes, carcinogens, and microorganisms that get into drinking water. This chapter presents information on the use of biomimetically developed nanobiosensors in the environment.
KeywordsBiomimeticEnvironmental monitoringNanoparticle
... This mask can be instantly utilized for primary diagnosis of coronavirus infections on-site and may help to reduce the time and clinical hassle of detecting the virus. [105] Daniels et al. reported a point-of-care diagnosis of SARS-CoV-2 based on a facemask-centered diagnostic platform, where an electrochemical biosensor analyzes the exhaled breath condensate within the mask. [106] During shortages of standard MAR, cloth masks are a potential alternative. ...
The unprecedented threat of COVID‐19 and the likelihood of other emerging infectious diseases have accentuated the need for sustainable and effective masks and respirators (MAR). MAR assists in minimizing the risk of infection and controlling the spread of pathogens. However, during the COVID‐19 pandemic, there was a worldwide scarcity of MAR due to unprecedented global demand. There are also notable limitations in commonly used MAR, such as low filtration efficiency, poor fit, non‐reusability, physiological impact, lack of biocompatibility and non‐biodegradability, and inability to kill pathogens. Therefore, there remains an unmet need for a comprehensive study focusing on potential materials and new technologies for MAR. Here we outline a comprehensive overview of the limitations of conventional MAR followed by required potential solutions (such as using nanofibers/graphene base filters/metal‐organic framework as filter media, laser scanning and 3D printing for fit and seal, applying antimicrobial nanomaterials coating on filter media, using reusable and biodegradable materials, developing high‐performing cloth masks, improving hydrophobicity, etc.). The information on potential materials and new technologies of MAR and research evidence outlined here can inform further research and development of high‐performing and sustainable respiratory protection technologies to improve the health and safety of the first responders and the community. The shortcomings of the commonly used conventional facemasks/respirators are pointed out, followed by the outline of potential materials and technologies that can inform the development of more effective technologies for respiratory protection.
Real-time monitoring of respiratory health is increasingly critical, particularly in addressing global health challenges such as Corona Virus Disease 2019 (COVID-19). Smart masks equipped with biosensing mechanisms represent a novel...
Point-of-care (POC) devices have become rising stars in the biosensing field, aiming at prognosis and diagnosis of diseases with a positive impact on the patient but also on healthcare and social care systems. Putting the patient at the center of interest requires the implementation of noninvasive technologies for collecting biofluids and the development of wearable platforms with integrated artificial intelligence–based tools for improved analytical accuracy and wireless readout technologies. Many electrical and electrochemical transducer technologies have been proposed for POC-based sensing, but several necessitate further development before being widely deployable. This review focuses on recent innovations in electrochemical and electrical biosensors and their growth opportunities for nanotechnology-driven multidisciplinary approaches. With a focus on analytical aspects to pave the way for future electrical/electrochemical diagnostics tests, current limitations and drawbacks as well as directions for future developments are highlighted.
This volume explores diverse applications for automated machine learning and predictive analytics. The content provides use cases for machine learning in different industries such as healthcare, agriculture, cybersecurity, computing and transportation.
Key highlights of this volume include topics on engineering for underwater navigation, and computer vision for healthcare and biometric applications.
Chapters 1-4 delve into innovative signal detection, biometric authentication, underwater AUV localization, and COVID-19 face mask detection. Chapters 5-9 focus on wireless pH sensing, differential pattern identification, economic considerations in off-grid hybrid power, high optimization of image transmission, and ANN-based IoT-bot traffic detection. Chapters 10-12 cover mixed-signal VLSI design, pre-placement 3D floor planning, and bio-mimic robotic fish. Finally, Chapters 13 and 14 explore underwater robotic fish and IoT-based automatic irrigation systems, providing a comprehensive overview of cutting-edge technological advancements.
The book is a resource for academics, researchers, educators and professionals in the technology sector who want to learn about current trends in intelligent technologies.
Rapid and accurate detection of respiratory virus aerosols is highlighted for virus surveillance and infection control. Here, we report a wireless immunoassay technology for fast (within 10 min), on-site (wireless and battery-free), and sensitive (limit of detection down to fg/L) detection of virus antigens in aerosols. The wireless immunoassay leverages the immuno-responsive hydrogel-modulated radio frequency resonant sensor to capture and amplify the recognition of virus antigen, and flexible readout network to transduce the immuno bindings into electrical signals. The wireless immunoassay achieves simultaneous detection of respiratory viruses such as severe acute respiratory syndrome coronavirus 2, influenza A H1N1 virus, and respiratory syncytial virus for community infection surveillance. Direct detection of unpretreated clinical samples further demonstrates high accuracy for diagnosis of respiratory virus infection. This work provides a sensitive and accurate immunoassay technology for on-site virus detection and disease diagnosis compatible with wearable integration.
This chapter presents an overview of the biomedical applications of electrospun nanofibers. Due to the impact of novel technological advancements on nanoplatform fabrication, this well-explored topic is still one of the most dynamic and exciting biomedically-oriented scientific fields. The entire chapter comprises three sections dealing with different applications of nanofibers linked by a shared element, which is the vital role of the nanostructure for the functional properties of the fibrous biomaterials under discussion. The first section introduces the key contribution of electrospun nanomaterials in developing injectable biomaterials for targeted nanomedicine. The second section reviews the interaction between fibrous hemostatic agents fabricated via electrospinning and blood, starting from basic principles to the final clinical applications. The last section is entirely focused on one of the most timely topics, such as the fabrication of innovative face masks. The evolution of face mask development is discussed in order to pave the way for providing an overview of the most challenging aspect of the fabrication of the next generation of face masks characterized by multifunctionality and the possibility to activate them on demand.
The rapidly expanding severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and its variants demand a continuous monitoring method through portable and wearable devices. Utilizing the rich surface chemistry and high chemical‐to‐electrical signal conversion of 2D MXene‐graphene heterostructure thin films, a field‐effect‐transistor (FET) sensor, which has a flexible substrate to be assembled onto the mask and combines with a Bluetooth system for wireless transmission is developed, to detect the influenza and SARS‐CoV‐2 viruses in air and breath. At first, the developed sensors are examined in the laboratory through direct contact with sensing targets in solution form. The results show a low limit of detection (LOD) of 1 fg mL⁻¹ for recombinant SARS‐CoV‐2 spike protein and 125 copies mL⁻¹ for inactivated influenza A (H1N1) virus with high specificity in differing recombinant SARS‐CoV‐2 spike protein and inactivated H1N1 virus. Then the sensors are tested under various simulated human breathing modes through controlled exposure to atomizer‐generated aerosols in an enclosed chamber and mask coverage. The results show the high sensitivity of the developed sensors under varying distances to the source, viral load, flow rate, and enclosed conditions. At last, clinical tests are carried out to demonstrate the robustness and potential field applications of the sensors.
Microwave resonance sensing has attracted significant interest due to its promising potential in developing ultracompact integrated sensors. For biomedical sensing applications, it is required to realize high sensitivity to tiny volumes of solution using such long microwave wavelengths. Here, a chiral microwave plasmonic resonator, which can induce exceptional point (EP) state based on the coalescence of non‐Hermitian dipole eigenmodes, is proposed. The intrinsically geometric asymmetry leads to strong asymmetry of non‐Hermitian Hamiltonian and strong coupling between the two non‐degenerate dipoles, hence resulting in significantly enhanced frequency splitting signals. Benefiting from the subwavelength dipole resonances, the proposed resonator has advantages of the EP state's high sensitivity to tiny targets and strong plasmonic wavelength compression. Its sensing performance is experimentally validated by metal scatterer detection and glucose solution measurement. The minimum detectable metal scatterer features a diameter of λ0/280 and a volume of 2.9 × 10⁻⁹ λ0³ (λ0 is free‐space wavelength). The solution volume under detection features a volume of 4.4 × 10⁻⁷ λ0³ and the reporting limit for glucose reaches 0.26 µmol. These results envision a feasible route for trace‐amount biomedical sensing at the microwave frequencies.
Human-infecting pathogens that transmit through the air pose a significant threat to public health. As a prominent instance, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused the COVID-19 pandemic has affected the world in an unprecedented manner over the past few years. Despite the dissipating pandemic gloom, the lessons we have learned in dealing with pathogen-laden aerosols should be thoroughly reviewed because the airborne transmission risk may have been grossly underestimated. From a bioanalytical chemistry perspective, on-site airborne pathogen detection can be an effective non-pharmaceutic intervention (NPI) strategy, with on-site airborne pathogen detection and early-stage infection risk evaluation reducing the spread of disease and enabling life-saving decisions to be made. In light of this, we summarize the recent advances in highly efficient pathogen-laden aerosol sampling approaches, bioanalytical sensing technologies, and the prospects for airborne pathogen exposure measurement and evidence-based transmission interventions. We also discuss open challenges facing general bioaerosols detection, such as handling complex aerosol samples, improving sensitivity for airborne pathogen quantification, and establishing a risk assessment system with high spatiotemporal resolution for mitigating airborne transmission risks. This review provides a multidisciplinary outlook for future opportunities to improve the on-site airborne pathogen detection techniques, thereby enhancing the preparedness for more on-site bioaerosols measurement scenarios, such as monitoring high-risk pathogens on airplanes, weaponized pathogen aerosols, influenza variants at the workplace, and pollutant correlated with sick building syndromes.
Wearable health sensors for an expanding range of physiological parameters have experienced rapid development in recent years and are poised to disrupt the way healthcare is tracked and administered. The monitoring of environmental contaminants with wearable technologies is an additional layer of personal and public healthcare and is also receiving increased focus. Wearable sensors that detect exposure to airborne viruses can alert wearers of viral exposure and prompt proactive testing and minimization of viral spread, benefitting their own health and decreasing community risk. With the high levels of asymptomatic spread of Coronavirus Disease 2019 (COVID‐19) observed during the pandemic, such devices can dramatically enhance the pandemic response capabilities in the future. To facilitate advancements in this area, this review summarizes recent research on airborne viral detection using wearable sensing devices, as well as technologies suitable for wearables. Since the low concentration of viral particles in the air poses significant challenges to detection, methods for airborne viral particle collection and viral sensing are discussed in detail. A special focus is placed on nucleic acid‐based viral sensing mechanisms due to their enhanced ability to discriminate between viral subtypes. Important considerations for integrating airborne viral collection and sensing on a single wearable device are also discussed.
Background
Nanotechnology is a cornerstone of the scientific advances witnessed over the past few years. Nanotechnology applications are extensively broad, and an overview of the main trends worldwide can give an insight into the most researched areas and gaps to be covered.
Objective
This document presents an overview of the trend topics of the three leading countries studying in this area, as well as Brazil for comparison.
Method
The data mining was made from the Scopus database and analyzed using the VOSviewer and Voyant Tools software.
Results
More than 44.000 indexed articles published from 2010 to 2020 revealed that the countries responsible for the highest number of published articles are The United States, China, and India, while Brazil is in the fifteenth position. Thematic global networks revealed that the standing-out research topics are health science, energy, wastewater treatment, and electronics. In a temporal observation, the primary topics of research are: India (2020), which was devoted to facing SARS-COV 2; Brazil (2019), which is developing promising strategies to combat cancer; China (2018), whit research on nanomedicine and triboelectric nanogenerators; the United States (2017) and the Global tendencies (2018) are also related to the development of triboelectric nanogenerators. The collected data are available on GitHub.
Conclusions
This study demonstrates the innovative use of data-mining technologies to gain a comprehensive understanding of nanotechnology's contributions and trends and highlights the diverse priorities of nations in this cutting-edge field.
Sensors suitable for wearable devices have many special characteristics compared to other sensors, such as stability, sensitivity, sensor volume, biocompatibility, etc. With the development of wearable technology, amazing wearable sensors have attracted a lot of attention, and some researchers have done a large number of technology explorations and reviews. However, previous surveys generally concerned a specified application and comprehensively reviewed the computing techniques for the signals required by this application, as well as how computing can promote data processing. There is a gap in the opposite direction, i.e., the fundamental data source actively stimulates application rather than from the application to the data, and computing promotes the acquisition of data rather than data processing. To fill this gap, starting with different parts of the body as the source of signal, the fundamental data sources that can be obtained and detected are explored by combining the three sensing principles, as well as discussing and analyzing the existing and potential applications of machine learning in simplifying sensor designs and the fabrication of sensors.
Viral particles bind to receptors through multivalent protein interactions. Such high avidity interactions on sensor surfaces are less studied. In this work, three polyelectrolytes that can form biosensing surfaces with different interfacial characteristics in probe density and spatial arrangement were designed. Quartz crystal microbalance, interferometry and atomic force microscopy were used to study their surface density and binding behaviors with proteins and virus particles. A multivalent adsorption kinetic model was developed to estimate the number of bonds from the viral particles bound to the polyelectrolyte surfaces. Experimental results show that the heterogeneous 3D surface with jagged forest-like structure enhances the virus capture ability by maximizing the multivalent interactions. As a proof of concept, specific coronavirus detection was achieved in spiked swab samples. These results indicate the importance of both probe density and their spatial arrangement on the sensing performance, which could be used as a guideline for rational biosensing surface design.
The outbreak of the recent Covid-19 pandemic changed many aspects of our daily life, such as the constant wearing of face masks as protection from virus transmission risks. Furthermore, it exposed the healthcare system’s fragilities, showing the urgent need to design a more inclusive model that takes into account possible future emergencies, together with population’s aging and new severe pathologies. In this framework, face masks can be both a physical barrier against viruses and, at the same time, a telemedical diagnostic tool. In this paper, we propose a low-cost, 3D-printed face mask able to protect the wearer from virus transmission, thanks to internal FFP2 filters, and to monitor the air quality (temperature, humidity, CO2) inside the mask. Acquired data are automatically transmitted to a web terminal, thanks to sensors and electronics embedded in the mask. Our preliminary results encourage more efforts in these regards, towards rapid, inexpensive and smart ways to integrate more sensors into the mask’s breathing zone in order to use the patient’s breath as a fingerprint for various diseases.
The Coronavirus disease 2019 (COVID-19) outbreak has urged the establishment of a global-wide rapid diagnostic system. Current widely-used tests for COVID-19 include nucleic acid assays, immunoassays, and radiological imaging. Immunoassays play an irreplaceable role in rapidly detecting COVID-19 and monitoring the patients for the assessment of their severity, risks of the immune storm, and prediction of treatment outcomes. Despite of the enormous needs for immunoassays, the widespread use of traditional immunoassay platforms is still limited by high cost and low automation, which are currently not suitable for point-of-care tests (POCTs). Microfluidic chips with the features of low consumption, high throughput, and integration, provide the potential to enable immunoassays for POCTs, especially in remote areas. Meanwhile, luminescence detection can be merged with immunoassays on microfluidic platforms for their good performance in quantification, sensitivity, and specificity. This review introduces both homogenous and heterogenous luminescence immunoassays with various microfluidic platforms. We also summarize the strengths and weaknesses of the categorized methods, highlighting their recent typical progress. Additionally, different microfluidic platforms are described for comparison. The latest advances in combining luminescence immunoassays with microfluidic platforms for POCTs of COVID-19 are further explained with antigens, antibodies, and related cytokines. Finally, challenges and future perspectives were discussed.
The worldwide pandemic of coronavirus disease—2019 (COVID-19) is a devastating and distressing scenario that highlights humanity’s inability to build fast diagnostic tools for emerging infectious diseases. However, the majority of existing approaches have a significant probability of false negatives, leading in patient diagnostic errors and prolonging therapy. Nanoparticles have shown significant improvement and have the potential to be used as a platform for quickly and accurately identifying viral infection. The relevance of nanoparticles is potential platforms for COVID-19 diagnostics was emphasized in this research. In addition, nanomaterials have surface chemistry, which may be beneficial for the bioconjugation of molecules, large surface potential, and a significant amplification impact on signals. Due to various potential benefits, metallic nanomaterials like gold, silver nanoparticles, and carbon-based nanomaterials (carbon nanotube and graphene), nanogels, and photonic crystals are utilized for biosensing applications. In compared to traditional techniques for identifying severe acute respiratory syndrome coronavirus—2 (SARS-CoV-2), this study covers the most relevant aspects of nanobiosensor-based diagnostics techniques. Additionally, major potential challenges and prospects associated with the advancement of these distinct sensors for SARS-CoV-2 detection are discussed in detail.
Volatile biomarkers play a significant signalling role in communication between biological cells living as individual entities or as mini-societies that sense, respond and adapt to changes in their environment. In this process, volatile biomarkers can leak into the blood, from which they can be secreted into most body fluids (blood, breath, skin, urine, saliva, feces, etc.), from which sensing devices can capture and interpret their chemical fingerprint to reflect any association with health disorders in a fast, easy, and minimally non-invasive manner.
This book introduces the concept of biomarkers within the body in terms of basic and translational sciences. It starts with a comprehensive review of the expression and mechanistic pathways involving volatile biomarkers at single cell and (micro)organism levels, cell-to-cell and cell-to-organism communications, and their secretion into body fluids. It discusses several ways for discovering and detecting the secreted biomarkers using mass spectrometry and other spectroscopic techniques. This is followed by an appraisal and translation of the accumulating knowledge from the laboratory to the Point-of-Care phase, using selective sensors as well as desktop and wearable artificial sensing devices, e.g., electronic noses and electronic skins, in conjugation with AI-assisted data processing and healthcare decision-making in diagnostics. The book offers an outlook into the challenges in the continuing development of volatile biomarkers and their wider availability to healthcare, which can be substantially improved. It should appeal to research groups in universities, start-up and large-scale industries associated in all aspects of biomedicine.
Face masks have been used as the most effective and economically viable preventive tool, which also creates a sense of social solidarity in collectively combatting the airborne health hazards. In spite of enormous research literature, massive production, and a competitive market, the use of modern age face masks-respirators (FMR) is restricted for specific purposes or during public health emergencies. It is attributed to lack of awareness, prominent myths, architect and manufacturing limitations, health concerns, and probable solid waste management. However, enormous efforts have been dedicated to address these issues through using modern age materials and textiles such as nanomaterials during mask fabrication. Conventional FMRs possess bottlenecks of breathing issues, skin problems, single use, fungal infections, communication barrier for differently abled, inefficiency to filter minute contaminants, sourcing secondary contamination and issue of solid-waste management upon usage. Contrary, FMR engineered with functional nanomaterials owing to the high specific surface area, unique physicochemical properties, and enriched surface chemistries address these challenges due to smart features like self-cleaning ability, biocompatibility, transparency, multiple usages, anti-contaminant, good breathability, excellent filtration capacity, and pathogen detecting and scavenging capabilities. This review highlights the state-of-the-art smart FMR engineered with different dimensional nanomaterials and nanocomposites to combat airborne health hazards, especially due to infectious outbreaks and air contamination. Besides, the myths and facts about smart FMR, associated challenges, potential sustainable solutions, and prospects for "point-of-action" intelligent operation of
The COronaVIrus Disease (COVID-19) is a newly emerging viral disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Rapid increase in the number of COVID-19 cases worldwide led the WHO to declare a pandemic within a few months after the first case of infection. Due to the lack of a prophylactic measure to control the virus infection and spread, early diagnosis and quarantining of infected as well as the asymptomatic individuals are necessary for the containment of this pandemic. However, the current methods for SARS-CoV-2 diagnosis are expensive and time consuming, although some promising and inexpensive technologies are becoming available for emergency use. In this work, we report the synthesis of a cheap, yet highly sensitive, cobalt-functionalized TiO2 nanotubes (Co-TNTs)-based electrochemical sensor for rapid detection of SARS-CoV-2 through sensing the spike (receptor binding domain (RBD)) present on the surface of the virus. A simple, low-cost, and one-step electrochemical anodization route was used for synthesizing TNTs, followed by an incipient wetting method for cobalt functionalization of the TNTs platform, which was connected to a potentiostat for data collection. This sensor specifically detected the S-RBD protein of SARS-CoV-2 even at very low concentration (range of 14 to 1400 nM (nano molar)). Additionally, our sensor showed a linear response in the detection of viral protein over the concentration range. Thus, our Co-TNT sensor is highly effective in detecting SARS-CoV-2 S-RBD protein in approximately 30 s, which can be explored for developing a point of care diagnostics for rapid detection of SARS-CoV-2 in nasal secretions and saliva samples.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads worldwide and leads to an unprecedented medical burden and lives lost. Neutralizing antibodies provide efficient blockade for viral infection and are a promising category of biological therapies. Here, using SARS-CoV-2 spike receptor-binding domain (RBD) as a bait, we generate a panel of humanized single domain antibodies (sdAbs) from a synthetic library. These sdAbs reveal binding kinetics with the equilibrium dissociation constant (KD) of 0.99-35.5 nM. The monomeric sdAbs show half maximal neutralization concentration (EC50) of 0.0009-0.07 µg/mL and 0.13-0.51 µg/mL against SARS-CoV-2 pseudotypes, and authentic SARS-CoV-2, respectively. Competitive ligand-binding experiments suggest that the sdAbs either completely block or significantly inhibit the association between SARS-CoV-2 RBD and viral entry receptor ACE2. Fusion of the human IgG1 Fc to sdAbs improve their neutralization activity by up to ten times. These results support neutralizing sdAbs as a potential alternative for antiviral therapies.
Exhaled breath samples had the highest positive rate (26.9%, n=52), followed by surface swabs (5.4%, n=242), and air samples (3.8%, n=26). COVID-19 patients recruited in Beijing exhaled millions of SARS-CoV-2 RNA copies into the air per hour. Exhaled breath emission may play an important role in the COVID-19 transmission.
Coronaviruses have received global concern since 2003, when an outbreak caused by SARS-CoV emerged in China. Later on, in 2012, the Middle-East respiratory syndrome spread in Saudi Arabia, caused by MERS-CoV. Currently, the global crisis is caused by the pandemic SARS-CoV-2, which belongs to the same lineage of SARS-CoV. In response to the urgent need of diagnostic tools, several lab-based and biosensing techniques have been proposed so far. Five main areas have been individuated and discussed in terms of their strengths and weaknesses. The cell-culture detection and the microneutralization tests are still considered highly reliable methods. The genetic screening, featuring the well-established Real-time polymerase chain reaction (RT-PCR), represents the gold standard for virus detection in nasopharyngeal swabs. On the other side, immunoassays were developed, either by screening/antigen recognition of IgM/IgG or by detecting the whole virus, in blood and sera. Next, proteomic mass-spectrometry (MS)-based methodologies have also been proposed for the analysis of swab samples. Finally, virus-biosensing devices were efficiently designed. Both electrochemical immunosensors and eye-based technologies have been described, showing detection times lower than 10 min after swab introduction. Alternative to swab-based techniques, lateral flow point-of-care immunoassays are already commercially available for the analysis of blood samples. Such biosensing devices hold the advantage of being portable for on-site testing in hospitals, airports, and hotspots, virtually without any sample treatment or complicated lab precautions.
Coughs and sneezes disperse a large number of droplets of varying size into the environment, and they transmit respiratory viral infections by direct or indirect physical contact, by droplets or inhalation of fine particulate droplet nuclei. Larger droplets in the cloud produced by coughing and sneezing settle quickly, and the force with which they are expelled determines how far they are dispersed. The respiratory droplets evaporate to form smaller droplet nuclei that carry infectious agents, remain suspended in air, and susceptible individuals farther away from the source could inhale them. The particle size distribution within the multi-phase cloud produced by coughs/sneezes changes with time and distance from the source depending on several environmental factors. After inhalation, larger respiratory droplets are filtered by the nose or deposit in the oropharynx, whereas smaller droplet nuclei are carried by the airstream into the lungs where their site of deposition depends on their mass, size and shape and is governed by various mechanisms. Airborne particles could also be produced by various aerosol generating procedures, such as suctioning or tracheal intubation, and by aerosol generators, especially jet nebulizers. Prevention of respiratory viral infections depends upon whether they are carried in respiratory droplets or as fine droplet nuclei (airborne or aerosol transmission). The SARS-CoV-2 virus that causes COVID-19 is mainly transmitted by respiratory droplets or by contact. Airborne transmission of this virus has not been established, but is possible under special circumstances. Appropriate protective measures are necessary to prevent transmission of SARS-CoV-2 virus in various settings. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
A homemade gold electrode is modified with a carbon nanotubes/gold nanoparticles nanocomposite to perform selective and sensitive electrochemical detection of dengue toxin. This nanostructured composite offers a large specific surface and a reactive interface allowing the immobilization of biological material. Dengue antibodies are immobilized on gold nanoparticles via covalent bonding for dengue toxin detection. The porous tridimensional network of carbon nanotubes and gold nanoparticles enhances the electrochemical signal and the overall performance of the sensor. After optimization, the system exhibits a high sensitivity of − 0.44 ± 0.01 μA per decade with wide linear range between 1 × 10⁻¹² and 1 × 10⁻⁶ g/mL at a working potential of 0.22 V vs Ag/AgCl. The extremely low detection limit (3 × 10⁻¹³ g/mL) ranks this immunosensor as one of the most efficient reported in the literature for the detection of recombinant viral dengue virus 2 NS1. This biosensor also offers good selectivity, characterized by a low response to various non-specific targets and assays in human serum. The outstanding performances and the reproducibility of the system place the biosensor developed among the best candidates for future medical applications and for early diagnosis of dengue fever.
Graphical abstract
Coronavirus disease 2019 (COVID-19) is a newly emerging human infectious disease caused by acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV). Based on the rapid increase in the rate of human infection, the World Health Organization (WHO) has classified the COVID-19 outbreak as a pandemic. Because no specific drugs or vaccines for COVID-19 are yet available, early diagnosis and management are crucial for containing the outbreak. Here, we report a field-effect transistor (FET)-based biosensing device for detecting SARS-CoV-2 in clinical samples. The sensor was produced by coating graphene sheets of FET with a specific antibody against SARS-CoV-2 spike protein. The performance of the sensor was determined using antigen protein, cultured virus, and nasopharyngeal swab specimens from COVID-19 patients. Our FET device could detect SARS-CoV-2 spike protein at concentrations of 1 fg/ml in PBS and 100 fg/ml clinical transport medium. In addition, the FET sensor successfully detected SARS-CoV-2 in culture medium (limit of detection [LOD]: 1.6 x 10¹ pfu/ml) and clinical samples (LOD: 2.42 x 10² copies/ml). Thus, we have successfully fabricated a promising FET biosensor for SARS-CoV-2; our device is a highly sensitive immunological diagnostic method for COVID-19 that requires no sample pretreatment or labeling.
A novel SARS-like coronavirus (SARS-CoV-2) recently emerged and is rapidly spreading in humans1,2. A key to tackling this epidemic is to understand the virus’s receptor recognition mechanism, which regulates its infectivity, pathogenesis and host range. SARS-CoV-2 and SARS-CoV recognize the same receptor - human ACE2 (hACE2)3,4. Here we determined the crystal structure of the SARS-CoV-2 receptor-binding domain (RBD) (engineered to facilitate crystallization) in complex with hACE2. Compared with the SARS-CoV RBD, a hACE2-binding ridge in SARS-CoV-2 RBD takes a more compact conformation; moreover, several residue changes in SARS-CoV-2 RBD stabilize two virus-binding hotspots at the RBD/hACE2 interface. These structural features of SARS-CoV-2 RBD enhance its hACE2-binding affinity. Additionally, we show that RaTG13, a bat coronavirus closely related to SARS-CoV-2, also uses hACE2 as its receptor. The differences among SARS-CoV-2, SARS-CoV and RaTG13 in hACE2 recognition shed light on potential animal-to-human transmission of SARS-CoV-2. This study provides guidance for intervention strategies targeting receptor recognition by SARS-CoV-2.
The outbreak of the novel coronavirus disease (COVID‐19) quickly spread all over China and to more than 20 other countries. Although the virus (SARS‐Cov‐2) nucleic acid RT‐PCR test has become the standard method for diagnosis of SARS‐CoV‐2 infection, these real‐time PCR test kits have many limitations. In addition, high false negative rates were reported. There is an urgent need for an accurate and rapid test method to quickly identify large number of infected patients and asymptomatic carriers to prevent virus transmission and assure timely treatment of patients.
We have developed a rapid and simple point‐of‐care lateral flow immunoassay which can detect IgM and IgG antibodies simultaneously against SARS‐CoV‐2 virus in human blood within 15 minutes which can detect patients at different infection stages. With this test kit, we carried out clinical studies to validate its clinical efficacy uses. The clinical detection sensitivity and specificity of this test were measured using blood samples collected from 397 PCR confirmed COVID‐19 patients and 128 negative patients at 8 different clinical sites. The overall testing sensitivity was 88.66% and specificity was 90.63%. In addition, we evaluated clinical diagnosis results obtained from different types of venous and fingerstick blood samples. The results indicated great detection consistency among samples from fingerstick blood, serum and plasma of venous blood. The IgM‐IgG combined assay has better utility and sensitivity compared with a single IgM or IgG test. It can be used for the rapid screening of SARS‐CoV‐2 carriers, symptomatic or asymptomatic, in hospitals, clinics, and test laboratories.
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Background Chest CT is used for diagnosis of 2019 novel coronavirus disease (COVID-19), as an important complement to the reverse-transcription polymerase chain reaction (RT-PCR) tests. Purpose To investigate the diagnostic value and consistency of chest CT as compared with comparison to RT-PCR assay in COVID-19. Methods From January 6 to February 6, 2020, 1014 patients in Wuhan, China who underwent both chest CT and RT-PCR tests were included. With RT-PCR as reference standard, the performance of chest CT in diagnosing COVID-19 was assessed. Besides, for patients with multiple RT-PCR assays, the dynamic conversion of RT-PCR results (negative to positive, positive to negative, respectively) was analyzed as compared with serial chest CT scans for those with time-interval of 4 days or more. Results Of 1014 patients, 59% (601/1014) had positive RT-PCR results, and 88% (888/1014) had positive chest CT scans. The sensitivity of chest CT in suggesting COVID-19 was 97% (95%CI, 95-98%, 580/601 patients) based on positive RT-PCR results. In patients with negative RT-PCR results, 75% (308/413) had positive chest CT findings; of 308, 48% were considered as highly likely cases, with 33% as probable cases. By analysis of serial RT-PCR assays and CT scans, the mean interval time between the initial negative to positive RT-PCR results was 5.1 ± 1.5 days; the initial positive to subsequent negative RT-PCR result was 6.9 ± 2.3 days). 60% to 93% of cases had initial positive CT consistent with COVID-19 prior (or parallel) to the initial positive RT-PCR results. 42% (24/57) cases showed improvement in follow-up chest CT scans before the RT-PCR results turning negative. Conclusion Chest CT has a high sensitivity for diagnosis of COVID-19. Chest CT may be considered as a primary tool for the current COVID-19 detection in epidemic areas.
Development of wearable devices for continuous respiration monitoring is of great importance for evaluating human health. Here, we propose a new strategy to achieve rapid respiration response by confining conductive polymers into 1D nanowires which facilitates the water molecules absorption/desorption and maximizes the sensor response to moisture. The nanowires arrays were fabricated through a low-cost nanoscale printing approach on flexible substrate. The nanoscale humidity sensor shows a high sensitivity (5.46%) and ultrafast response (0.63 s) when changing humidity between 0 and 13% and can tolerate 1000 repetitions of bending to a curvature radius of 10 mm without influencing its performance. Benefited by its fast response and low power assumption, the humidity sensor was demonstrated to monitor human respiration in real time. Different respiration patterns including normal, fast and deep respiration can be distinguished accurately.
The demand for fast and ultratrace biomarkers detection is increasing in bioanalytical chemistry. In this work, highly ordered nanowires array and sensor integration are achieved with nanoscale printing approach. Negatively charged poly(3,4‐ethylenedioxythiophene)–poly(styrenesulfonate) doped with positively charged PEGylated biotin‐derivatized polyelectrolytes results a direct biofunctionalization on the nanowire surface without multiple postmodification steps. It provides homogeneous dispersed biofunctional sites and nonfouling surface on the nanowires. The ordered nanowires array enables the immunosensor to detect biotargets quickly and ultrasensitively. The nanowires impedimetric immunosensor is demonstrated for specific biomarkers detection and achieved a minimum responsive concentration as low as 10 pg mL−1 for protein biomarker and 10 CFU mL−1 for pathogen. A kind of biotin functionalization ink is achieved by doping with PEGylated biotin‐derivatized polyelectrolytes which enables a direct biofunctionalization on the nanowire surface. Then an immunosensor based on highly ordered nanowires array is fabricated by nanoscale printing approach. This sensor can be a general platform for different materials and various bioanalytical applications with ultrahigh sensitivity, trace detection, and fast response.
Viral aerosols can lead to respiratory viral infections with high infectivity. About 90% of people’s time is spent in closed environments. A few studies have pointed out that the ventilation systems in air handling units (AHUs) that treat and transmit a new synthetic clean and conditioned environment can also spread and transport viral particles in buildings. The aim of this work is to study the characterization of adenovirus, a DNA non-enveloped respiratory virus, on the F7 fiberglass filter used in AHUs. In this study, an experimental setup simulating an AHU was used. The SYBR® QPCR, Electrical Low-Pressure Impactor (ELPI™) and Scanning Mobility Particle Sizer (SMPS™) were used to detect, measure and characterize the aerosolized adenovirus solution. The characterization results showed that the nebulized adenovirus could be aerosolized in different forms associated or not with cell debris and proteins. The quantification and level of infectivity of adenovirus demonstrated that viruses passed through filters and remained infectious up- and downstream of the system during the 25 min of aerosolization. This study showed that AHUs should be considered an indoor source of viral contamination.
Exhaled breath collection has long been recognized as requiring the least invasive methods of the biological fluids and so is preferred for environmental and public health studies. This commentary describes how breath biomonitoring is generally preferred for certain logistical reasons in public health and occupational biomonitoring. Three different fractions of exhaled breath are considered: gas-phase, liquid condensate, and aerosols. The focus is on the exhaled breath aerosol (EBA) fraction and the development of targeted sampling and analysis methods. Specifically, the biological constituents found in dried aerosols are wiped or extracted from respiratory masks or surfaces and subsequently reconstituted in the laboratory for immunochemical or mass spectrometric analysis. This avoids logistical issues in the field regarding whole-breath or condensed liquid sampling and transport and represents the simplest non-invasive medium for biological assessment.
A wearable skin hydration sensor in the form of a capacitor is demonstrated based on skin impedance measurement. The capacitor consists of two interdigitated or parallel electrodes that are made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. The flexible and stretchable nature of the AgNW/PDMS electrode allows conformal contact to the skin. The hydration sensor is insensitive to the external humidity change and is calibrated against a commercial skin hydration system on an artificial skin over a wide hydration range. The hydration sensor is packaged into a flexible wristband, together with a network analyzer chip, a button cell battery, and an ultralow power microprocessor with Bluetooth. In addition, a chest patch consisting of a strain sensor, three electrocardiography electrodes, and a skin hydration sensor is developed for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless, and continuous monitoring of skin hydration and other health parameters.
Viral infectious diseases can erupt unpredictably, spread rapidly, and ravage mass populations. Although established methods, such as polymerase chain reaction, virus isolation, and next-generation sequencing have been used to detect viruses, field samples with low virus count pose major challenges in virus surveillance and discovery. We report a unique carbon nanotube size-tunable enrichment microdevice (CNT-STEM) that efficiently enriches and concentrates viruses collected from field samples. The channel sidewall in the microdevice was made by growing arrays of vertically aligned nitrogen-doped multiwalled CNTs, where the intertubular distance between CNTs could be engineered in the range of 17 to 325 nm to accurately match the size of different viruses. The CNT-STEM significantly improves detection limits and virus isolation rates by at least 100 times. Using this device, we successfully identified an emerging avian influenza virus strain [A/duck/PA/02099/2012(H11N9)] and a novel virus strain (IBDV/turkey/PA/00924/14). Our unique method demonstrates the early detection of emerging viruses and the discovery of new viruses directly from field samples, thus creating a universal platform for effectively remediating viral infectious diseases.
Suspensions of transmissible gastroenteritis virus (TGEV), a porcine coronavirus, were nebulized at rates of 0.1–0.2ml/min
into moving air using a Collison nebulizer or a plastic medical nebulizer operating at pressures ranging from 7 to 15psi.
The airborne viruses were collected on heating, ventilating, and air conditioning (HVAC) filters in an experimental apparatus
and also sampled upstream of these test filters using AGI-30 and BioSampler impinger samplers. To study the effects of relative
humidity (RH) on TGEV collection by the filters and samplers, the virus was nebulized into air at 30, 50, 70, and 90% RH.
There were no significant changes in virus titer in the nebulizer suspension before and after nebulization for either nebulizer
at any of the pressures utilized. Aerosolization efficiency – the ratio of viable virus sampled with impingers to the quantity
of viable virus nebulized – decreased with increasing humidity. BioSamplers detected more airborne virus than AGI-30 samplers
at all RH levels. This difference was statistically significant at 30 and 50% RH. Nebulizer type and pressure did not significantly
affect the viability of the airborne virus. Virus recovery from test filters relative to the concentration of virus in the
nebulizer suspension was less than 10%. The most and the least virus were recovered from filter media at 30% and 90% RH, respectively.
The results suggest that TGEV, and perhaps other coronaviruses, remain viable longer in an airborne state and are sampled
more effectively at low RH than at high humidity.
Avian influenza virus (AIV) subtype H5N1 was first discovered in the 1990 s and since then its emergence has become a likely source of a global pandemic and economic loss. Currently accepted gold standard methods of influenza detection, viral culture and rRT-PCR, are time consuming, expensive and require special training and laboratory facilities. A rapid, sensitive, and specific screening method is needed for in-field or bedside testing of AI virus to effectively implement quarantines and medications. Therefore, the objective of this study was to improve the specificity and sensitivity of an impedance biosensor that has been developed for the screening of AIV H5. Three major components of the developed biosensor are immunomagnetic nanoparticles for the separation of AI virus, a microfluidic chip for sample control and an interdigitated microelectrode for impedance measurement. In this study polyclonal antibody against N1 subtype was immobilized on the surface of the microelectrode to specifically bind AIV H5N1 to generate more specific impedance signal and chicken red blood cells (RBC) were used as biolabels to attach to AIV H5N1 captured on the microelectrode to amplify impedance signal. RBC amplification was shown to increase the impedance signal change by more than 100% compared to the protocol without RBC biolabels, and was necessary for forming a linear calibration curve for the biosensor. The use of a second antibody against N1 offered much greater specificity and reliability than the previous biosensor protocol. The biosensor was able to detect AIV H5N1 at concentrations down to 10(3) EID(50)ml(-1) in less than 2h.
Airborne pathogens causing infectious diseases are often highly transmittable between humans. Therefore, an airborne pathogen-monitoring system capable of on-site detection and identification would aid tremendously in preventing and controlling the early stages of pathogen spread. Here, we describe an integrated sampling/monitoring platform for on-site and real-time detection of airborne viruses. We used MS2 bacteriophage and avian influenza virus (AIV) H1N1 to evaluate bioaerosol sampling and detection performance of the platform. Our results show that, within 20 min, aerosolized viruses can be detected using the signal of near-infrared (NIR)-to-NIR nanoprobes. The pretreatment of the sampling pad improved the transfer efficiency of MS2 viruses to the detection zone, compared to an untreated pad. Our platform could detect concentrations as low as 104.294 50% egg infectious dose (EID50)/m3 AIVs collected from a cloacal swab sample (104.838 EID50/mL). These results indicate that our sampling/monitoring platform could be applied for the early detection of biological hazards in various fields.
To manage the COVID-19 pandemic, development of rapid, selective, sensitive diagnostic systems for early stage β-coronavirus severe acute respiratory syndrome (SARS-CoV-2) virus protein detection is emerging as a necessary response to generate the bioinformatics needed for efficient smart diagnostics, optimization of therapy, and investigation of therapies of higher efficacy. The urgent need for such diagnostic systems is recommended by experts in order to achieve the mass and targeted SARS-CoV-2 detection required to manage the COVID-19 pandemic through the understanding of infection progression and timely therapy decisions. To achieve these tasks, there is a scope for developing smart sensors to rapidly and selectively detect SARS-CoV-2 protein at the picomolar level. COVID-19 infection, due to human-to-human transmission, demands diagnostics at the point-of-care (POC) without the need of experienced labor and sophisticated laboratories. Keeping the above-mentioned considerations, we propose to explore the compartmentalization approach by designing and developing nanoenabled miniaturized electrochemical biosensors to detect SARS-CoV-2 virus at the site of the epidemic as the best way to manage the pandemic. Such COVID-19 diagnostics approach based on a POC sensing technology can be interfaced with the Internet of things and artificial intelligence (AI) techniques (such as machine learning and deep learning for diagnostics) for investigating useful informatics via data storage, sharing, and analytics. Keeping COVID-19 management related challenges and aspects under consideration, our work in this review presents a collective approach involving electrochemical SARS-CoV-2 biosensing supported by AI to generate the bioinformatics needed for early stage COVID-19 diagnosis, correlation of viral load with pathogenesis, understanding of pandemic progression, therapy optimization, POC diagnostics, and diseases management in a personalized manner.
From 2002 to 2019, three deadly human coronaviruses (hCoVs), severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle Eastern respiratory syndrome coronavirus (MERS‐CoV) and severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) emerged to produce outbreaks of SARS, MERS and coronavirus disease 2019 (Covid‐19), respectively. All three hCoVs are members of the Betacoronavirus genus in the subfamily Orthocoronavirinae and share many similarities in virology and epidemiology. However, the pattern and scale of Covid‐19 global spread is similar to 2009 pandemic H1N1 influenza (H1N1pdm09), rather than SARS or MERS. Covid‐19 exhibits high viral shedding in the upper respiratory tract at an early stage of infection, and has a high proportion of transmission competent individuals that are pre‐symptomatic, asymptomatic and mildly symptomatic, characteristics seen in H1N1pdm09 but not in SARS or MERS. These two traits of Covid‐19 and H1N1pdm09 result in reduced efficiency in identification of transmission sources by symptomatic screening and play important roles in their ability to spread unchecked to cause pandemics. To overcome these attributes of Covid‐19 in community transmission, identifying the transmission source by testing for virus shedding and interrupting chains of transmission by social distancing and public masking are required.
Sensitive virus detection method applicable for an early stage increases the probability of survival. Here, we develop a simple and rapid detection strategy for the detection of Hepatitis E virus (HEV) by an electrocatalytic water oxidation reaction (WOR) using Platinum (Pt)-incorporated cobalt (Co)-based zeolite imidazole framework (ZIF-67). The surface cavity of ZIF-67 enables the rich-loading of Pt NPs, and subsequent calcination etches the cavity, promoting the electrocatalytic activity of Pt-Co3O4 HCs. The Pt-Co3O4 HCs shows an excellent behavior for WOR due to the synergistic interaction of Pt and Co3O4, evaluated by voltammetry and chronoamperometry. The synthesized Pt-Co3O4 HCs are conjugated with Anti-HEV antibody (Ab@Pt-Co3O4 HCs), the electrocatalytic activity of Ab@Pt-Co3O4 HCs is combined with antibody-conjugated magnetic nanoparticles (MNPs) for HEV detection by magneto-and-nanocomposite sandwich immunoassay. The sensor is challenged to detect the HEV in spiked serum samples and HEV G7 genotypes collected from the cell culture supernatant, reaching a low limit of detection down to 61 RNA copies mL-1. This work establishes a free-indicator one-step approach with the controlled design of Pt-Co3O4 HCs, which presents an effective WOR technique for virus detection in neutral pH solution, extending the electrocatalytic study in the future integrated biosensing systems.
In March of 2020, the World Health Organization declared a pandemic of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The pandemic led to a shortage of N95-grade filtering facepiece respirators (FFRs), especially surgical-grade N95 FFRs for protection of healthcare professionals against airborne transmission of SARS-CoV-2. We and others have previously reported promising decontamination methods that may be applied to the recycling and reuse of FFRs. In this study we tested disinfection of three viruses including SARS-CoV-2, dried on a piece of meltblown fabric, the principal component responsible for filtering of fine particles in N95-level FFRs, under a range of temperatures (60-95˚C) at ambient or 100% relative humidity (RH) in conjunction with filtration efficiency testing. We found that heat treatments of 75˚C for 30 min or 85˚C for 20 min at 100% RH resulted in efficient decontamination from the fabric of SARS-CoV-2, human coronavirus NL63 (HCoV-NL63), and another enveloped RNA virus, chikungunya virus vaccine strain 181/25 (CHIKV-181/25), without lowering the meltblown fabric's filtration efficiency.
Since its emergence late in 2019, the COVID-19 pandemic continues to exude major public health and socio-economic burden globally. South Africa is currently the epicenter for the pandemic in Africa. This study is based on the use of a compartmental model to analyse the transmission dynamics of the disease in South Africa. A notable feature of the model is the incorporation of the role of environmental contamination by COVID-infected individuals. The model, which is fitted and parametrized using cumulative mortality data from South Africa, is used to assess the impact of various control and mitigation strategies. Rigorous analysis of the model reveals that its associated continuum of disease-free equilibria is globally-asymptotically stable whenever the control reproduction number is less than unity. The epidemiological implication of this result is that the disease will eventually die out, particularly if control measures are implemented early and for a sustainable period of time. For instance, numerical simulations suggest that if the lockdown measures in South Africa were implemented a week later than the 26 March, 2020 date it was implemented, this will result in the extension of the predicted peak time of the pandemic, and causing about 10% more cumulative deaths. In addition to illustrating the effectiveness of self-isolation in reducing the number of cases, our study emphasizes the importance of surveillance testing and contact tracing of the contacts and confirmed cases in curtailing the pandemic in South Africa.
The novel coronavirus (COVID-19), average size 100nm (nano-aerosol), can be aerosolized by coughing, sneezing, and breathing from infected persons. The airborne carrier for the COVID-19 can be tiny droplets and particulates from infected person, fine suspended mists (humidity) in air, or ambient aerosols in air. To-date, unfortunately there are no test standards for nano-aerosols. A goal in our study is to develop a filter with 90% capture on 100nm COVID-19 with pressure drop of less than 30Pa (3.1mm water). There are two challenges. First, this airborne bio-nanoaerosol (combined virus and carrier) is amorphous. Second, unlike standard laboratory tests on NaCl crystals and test oil (DOP) droplets, these polydispersed aerosols are of different sizes and can interact among themselves before simultaneously challenging the filter, e.g. facemask. For the first time, we have studied these two effects using ambient aerosols (simulating the bio-nanoaerosols of coronavirus plus carrier of different shapes and sizes) to challenge electrostatically charged multilayer nanofiber filters. This problem is fundamentally complicated due to mechanical and electrostatic interactions among aerosols of different sizes with induced charges of different magnitudes.
The test filters were arranged in 2, 4, and 6 multiple-modules stack-up with each module having 0.765 g/m² of charged PVDF nanofibers (mean diameter 525±191nm). This configuration minimized electrical interference among neighboring charged nanofibers and reduced flow resistance in the filter. For ambient aerosol size greater than 80nm (applicable to the smallest COVID-19), the electrostatic effect contributes 100 - 180% more efficiency to the existing mechanical efficiency (due to diffusion and interception) depending on the number of modules in the filter. By stacking-up modules to increase fiber basis weight in the filter, a 6-layer charged nanofiber filter achieved 88%, 88% and 96% filtration efficiency for, respectively, 55nm, 100nm and 300nm ambient aerosol. This is very close to attaining our set goal of 90%-efficiency on the 100nm ambient aerosol. The pressure drop for the 6-layer nanofiber filter was only 26Pa (2.65 mm water column) which was below our goal of 30Pa (3.1mm water). For the test multi-module filters, a high ‘quality factor’ (efficiency-to-pressure-drop ratio) of about 0.1 to 0.13Pa⁻¹ can be consistently maintained, which was far better than conventional filters.
Using the same PVDF 6-layer charged nanofiber filter, laboratory tests results using monodispersed NaCl aerosols of 50, 100, and 300nm yielded filtration efficiency, respectively, 92%, 94% and 98% (qualified for N98 standard) with same pressure drop of 26Pa. The 2-6% discrepancy in efficiency for the NaCl aerosols was primarily attributed to the absence of interaction among aerosols of different sizes. This discrepancy can be further reduced with increase number of modules in the filter and for larger 300nm aerosol. The 6-layer charged nanofiber filter was qualified as a N98 respirator (98% efficiency for 300nm NaCl aerosols) but with pressure drop of only 2.65-mm water which was 1/10 below conventional N95 with 25-mm (exhaling) to 35-mm (inhaling) water column, and also far below that of conventional N98! The 6-layer charged PVDF nanofiber filter provides good personal protection against airborne COVID-19 virus and nano-aerosols from pollution based on the N98 standard, yet it is at least 10X more breathable than a conventional N98 respirator.
Viruses pose serious infectious diseases threats to human and animals. To significantly decrease the mortality and morbidity caused by virus infection, there is an urgent need of sensitive and rapid point-of-care platforms for virus detection, especially in low-resource settings. Herein, we developed a smartphone-based point-of-care platform for highly sensitive and selective detecting of avian influenza virus based on nanomaterial-enabled colorimetric detection. The 3D nano-structures, which serve as scaffold for antibody conjugation to capture avian influenza virus, are made on PDMS herringbone structures with a ZnO nanorods template. After virus capture, on-chip gold nanoparticles-based colorimetric reaction allows virus detection by naked eyes with a detection limit of 2.7×104 EID50/ml, which is one order of magnitude better than that of conventional fluorescence-based ELISA. Furthermore, a smartphone imaging system with data processing capability further improves the detection limit, reaching down to 8 ×103 EID50/ml. The entire virus capture and detection process can be completed in 1.5 hours. We envision that this point-of-care microfluidic system integrated with smartphone imaging and colorimetric detection would provide a fast, cheap, sensitive and user-friendly platform for virus detection in low-resource settings.
The deposition of micro- and nanolitre volumes is crucial in sessile droplet microfluidic systems. Several techniques exist for the fabrication of surfaces with patterned wettabilities; however, many of these fabrication techniques are time-consuming and complex. Here, we present a device that allows for deposition of multiple droplets within seconds followed by directed evaporative preconcentration. Hydrophobic-coated glass substrates are fashioned with hydrophilic surface energy traps (SETs) using picosecond laser micromachining. SETs can capture nanolitre volumed droplets of both aqueous and organic liquids through discontinuous dewetting. Modification of the machined hydrophilic shape yields a passive mechanism that preconcentrates analyte through evaporation. Studies and optimizations of SET parameters/dimensions (laser power, laser passes, ring/patch diameter) and their effect on patch wettability and degree of preconcentration are presented. As a demonstration, the optimized platform was used to improve the colourimetric detection of cadmium-containing aqueous samples. The optimized SET design demonstrated an 18-fold increase in colourimetric sensitivity compared to conventional milled SETs, suggesting the design would be well-suited for trace analysis. The evaporative preconcentration was also applied to MALDI-IMS analysis of peptides where it resulted in improved uniformity of deposited analyte and decreased analysis times. The rapid droplet deposition and directed evaporative approach can be tailored to provide different concentration factors and is compatible with a wide variety of detection schemes.
Flexible ammonia (NH3) sensors based on one-dimensional nanostructures have attracted great attention due to their high flexibility and low-power consumption. However, it is still challenging to reliably and cost-effectively fabricate ordered nanostructure-based flexible sensors. Herein, a smartphone-enabled fully integrated system based on a flexible nanowire sensor was developed for real-time NH3 monitoring. Highly aligned, sub-100 nm nanowires on a flexible substrate fabricated by facile and low-cost soft lithography were used as sensitive elements to produce impedance response. The detection signals were sent to a smartphone and displayed on the screen in real time. This nanowire-based sensor exhibited robust flexibility and mechanical durability. Moreover, the integrated NH3 sensing system presented enhanced performance with a detection limit of 100 ppb, as well as high selectivity and reproducibility. The power consumption of the flexible nanowire sensor was as low as 3 μW. By using this system, measurements were carried out to obtain reliable information about the spoilage of foods. This smartphone-enabled integrated system based on a flexible nanowire sensor provided a portable and efficient way to detect NH3 in daily life.
Zika virus (ZIKV) infection is an emerging pandemic threat to humans that can be fatal in newborns. Advances in digital health systems and nanoparticles can facilitate the development of sensitive and portable detection technologies for timely management of emerging viral infections. Here we report a nanomotor-based bead-motion cellphone (NBC) system for the immunological detection of ZIKV. The presence of virus in a testing sample results in the accumulation of platinum (Pt)-nanomotors on the surface of beads, causing their motion in H2O2 solution. Then the virus concentration is detected in correlation with the change in beads motion. The developed NBC system was capable of detecting ZIKV in samples with virus concentrations as low as 1 particle/μL. The NBC system allowed a highly specific detection of ZIKV in the presence of the closely related dengue virus and other neurotropic viruses, such as herpes simplex virus type 1 and human cytomegalovirus. The NBC platform technology has the potential to be used in the development of point-of-care diagnostics for pathogen detection and disease management in developed and developing countries.
A mathematical model is developed for the impedance response of immobilized glucose oxidase electrochemical biosensors. The coupling between the homogeneous reactions and heterogeneous reactions considered in the model included anomerization between α-d-glucose and β-d-glucose and four reversible enzymatic catalytic reactions transforming β-d-glucose and oxygen into gluconic acid and hydrogen peroxide. The electroactive hydrogen peroxide was considered to be reversibly oxidized or reduced at the electrode. The electrochemical system was modeled mathematically as a one-dimensional boundary-value problem and solved by use of Newman's BAND algorithm. The corresponding impedance was calculated for each specified frequency. The resulted limiting current, reaction profiles, and impedance response provide insights into the influence of system parameters such as interstitial glucose concentration and enzymatic rate constants. This model has a potential application in predicting sensor design and diagnosing sensor failure mechanisms.
The extraordinary electronic and photonic features render black phosphorus (BP) an important material for the development of novel electronics and optoelectronics. Despite the recent progress in the preparation of few-layered BP flakes, scalable synthesis of large-size, pristine BP flakes represents one of the main challenges. Here we demonstrate an electrochemical delamination strategy, based on the intercalation of diverse cations in non-aqueous electrolytes, to peel off bulk BP crystals into few-layer, defect-free flakes. The interplay between tetra-n-butyl-ammonium cations and bisulfate anions promotes high exfoliation yield up to 78 % and large BP flakes up to 20.6 µm. Bottom-gate and bottom-contact field effect transistors based on few-layered single BP flakes exhibit high hole mobility of 252±18 cm2 V-1 s-1 and remarkable on/off ratio of (1.2±0.15)×105 at 143 K under vacuum. This efficient and scalable delamination method holds great promise in the future development of BP-based composites and optoelectronic devices.
Principles of Bacterial Detection: Biosensors, Recognition Receptors and Microsystems presents a significant and up-to-date review of various integrated approaches for bacterial detection. Distinguished engineers and scientists from key institutions worldwide have contributed chapters that provide a deep analysis of their particular subject; at the same time, each topic is framed within the context of this integrated approach. This work is a comprehensive approach to bacterial detection requiring a thorough knowledge of the subject and an effective integration of other disciplines in order to appropriately convey the state-of-the-art fundamentals and applications of the involved disciplines.
The book consists of four parts:
The first part provides an introduction to pathogenic bacteria and sampling techniques and an overview of the rapid microbiological methods.
The second part describes the different transducers used for the detection of bacteria. It covers the theory behind each technique and provides a state-of-the-art review of all the new technologies used for the detection of bacteria in detail. Strategies and future prospects are suggested at the end of each chapter for developing future technologies to achieve a better sensitivity and swifter detection of bacteria.
The third part gives an account of the different recognition receptors used in the various methods for the detection of bacteria. It describes in detail the use of immunoassays, nucleic acids, oligonucleotide microarrays, carbohydrates, aptamers, protein microarrays, bacteriophages, phage displays and molecular imprinted polymers as recognition elements.
The fourth part covers the microsystems used for detection/identification and bacterial manipulation such as bacteria lysis and PCR in microfluidics, dielectrophoresis, ultrasonic manipulation techniques and mass spectrometry techniques.
Students and researchers who need a solid foundation or reference and practitioners interested in discovering more about the state-of-the-art methods of bacterial detection will find this book invaluable. This book is directed at academics and undergraduate and postgraduate students who work in areas related to bacterial detection. It may also serve as an important reference for professionals working in different fields, including biomedical science, physical science, microsystems engineering, nanotechnology, veterinary science, food quality assurance, bioterrorism and security as well as health surveillance.
Metal and metal oxides with various nanostructures have been widely studied in non-enzymatic glucose sensing. In this work, we report an efficient catalyst platform, which is made of three-dimensional copper foam (CF) skeleton and copper oxide nanowire arrays (CuONWA), is used to construct glucose sensor. The three-dimensional CuONWA/CF was synthesized via a facile wet-chemical method and subsequent annealing. The CuONWA is evenly covered by CuO nanoflowers. The morphology and composition of the platform were characterized. The nanowire arrays and nanoflowers both enhanced the electrocatalytic performance of the integrated electrode via greatly increasing the surface area of the CF substrate. The electrocatalytic properties of the non-enzymatic glucose sensor were characterized by a series of electrochemical measurements. The sensor exhibits excellent performance, with a linear range of 0.10 μM ∼ 0.50 mM, a sensitivity of 32330 μA mM⁻¹ cm⁻², a low limit of detection of 20 nM (S/N = 3), excellent selectivity, reproducibility, and stability. The sensor was also used for glucose sensing in human serum and Wahaha ice black tea, with relative standard deviations (for n = 6) of 3.15% and 2.43%, respectively.
It is well known, that bioaerosols possess hazard to human health. Bioaerosols could be a cause of various severe diseases. Rapid and precise detection of airborne pathogens in different environments has received considerable attention in recent years. Earlier, we explored a Surface Plasmon Resonance (SPR) protocol in conjunction with our recently developed personal bioaerosol sampler for rapid detection of airborne viruses. The developed label-free approach has been verified under controlled laboratory conditions. The immunosensor based technique was capable of detecting airborne virus in a broad range of concentrations within minutes with high accuracy and specificity.
This project is a logical continuation of our previous study where we describe the performance evaluation study of two immunosensor types (differed in surface chemistry) for direct viral detection. Common viral surrogate MS2 bacteriophage was employed as a model organism. The detection limits of developed SPR techniques were found to be 1.12×106 PFU/mL and 2.2×107 PFU/mL for the COOH1 and COOH5 sensor types respectively. Our data confirmed that COOH1 based sensor is more sensitive and robust regarding detection of small viral objects like MS2 phage.
The combination of SPR procedure with the bioaerosol sampler allowed detecting virus in the air within less than two minutes. The minimal detectable viral concentration in the air for 1 minute of sampling time was found to be 1.9×107 PFU per litre. Our findings justify that the SPR technique is fully suitable for the bioaerosol monitoring applications. The proposed technology, based on the direct detection of viral aerosols, could be applied to various viral pathogens infectious to animals or humans, and be further realised in a concept of portable real-time bioaerosol monitor.
Antibody mimic proteins (AMPs) are polypeptides that bind to their target analytes with high affinity and specificity, just like conventional antibodies, but are much smaller in size (2-5 nm, less than 10 kDa). In this report, we describe the first application of AMP in the field of nanobiosensors. In(2)O(3) nanowire based biosensors have been configured with an AMP (Fibronectin, Fn) to detect nucleocapsid (N) protein, a biomarker for severe acute respiratory syndrome (SARS). Using these devices, N protein was detected at subnanomolar concentration in the presence of 44 microM bovine serum albumin as a background. Furthermore, the binding constant of the AMP to Fn was determined from the concentration dependence of the response of our biosensors.
American journal of respiratory and critical care medicine
- R Dhand
- J Li
Dhand, R., Li, J., 2020. American journal of respiratory and critical care medicine 202, 651-659.
- S M Garba
- J M S Lubuma
- B Tsanou
- H A Hussein
- R Y A Hassan
- M Chino
- F Febbraio
Garba, S.M., Lubuma, J.M.S., Tsanou, B., 2020. Mathematical Biosciences 328, 108441.
Hussein, H.A., Hassan, R.Y.A., Chino, M., Febbraio, F., 2020. Sensors 20, 4289.
- S Islam
- S Shukla
- V K Bajpai
- Y.-K Han
- Y S Huh
- A Kumar
- A Ghosh
- S Gandhi
Islam, S., Shukla, S., Bajpai, V.K., Han, Y.-K., Huh, Y.S., Kumar, A., Ghosh, A., Gandhi, S., 2019.
Biosensors and Bioelectronics 126, 792-799.
- W W Leung
- .-F Sun
Leung, W.W.-F., Sun, Q., 2020. Sep Purif Technol 245, 116887.
- W Liu
- L Liu
- G Kou
- Y Zheng
- Y Ding
- W Ni
- Q Wang
- L Tan
- W Wu
- S Tang
- Z Xiong
- S Zheng
Liu, W., Liu, L., Kou, G., Zheng, Y., Ding, Y., Ni, W., Wang, Q., Tan, L., Wu, W., Tang, S., Xiong, Z.,
Zheng, S., 2020. Journal of Clinical Microbiology 58, e00461-e00420.
- J D Pleil
- M A G Wallace
- M C Madden
Pleil, J.D., Wallace, M.A.G., Madden, M.C., 2018. Journal of Breath Research 12, 027110.
- C Riquelme
- D Escors
- J Ortego
- C M Sanchez
- B Uzelac-Keserovic
- K Apostolov
- L Enjuanes
Riquelme, C., Escors, D., Ortego, J., Sanchez, C.M., Uzelac-Keserovic, B., Apostolov, K., Enjuanes, L.,
2002. Emerging Infectious Disease Journal 8, 869-870.
- G Seo
- G Lee
- M J Kim
- S.-H Baek
- M Choi
- K B Ku
- C.-S Lee
- S Jun
- D Park
- H G Kim
- S.-J Kim
- J.-O Lee
- B T Kim
- E C Park
- S I Kim
Seo, G., Lee, G., Kim, M.J., Baek, S.-H., Choi, M., Ku, K.B., Lee, C.-S., Jun, S., Park, D., Kim, H.G.,
Kim, S.-J., Lee, J.-O., Kim, B.T., Park, E.C., Kim, S.I., 2020. ACS Nano 14, 5135-5142.
- B Tucker
- M Hermann
- A Mainguy
- R Oleschuk
Tucker, B., Hermann, M., Mainguy, A., Oleschuk, R., 2020. Analyst 145, 643-650.
Sensors 20, 5871. World Health, O., 2020. World Health Organization
- B S Vadlamani
- T Uppal
- S C Verma
- M Misra
Vadlamani, B.S., Uppal, T., Verma, S.C., Misra, M., 2020. Sensors 20, 5871.
World Health, O., 2020. World Health Organization, Geneva.
Reviews in Medical Virology 31, e2171
- Z Wu
- D Harrich
- Z Li
- D Hu
- D Li
- Y Xia
- Y Chen
- Y Tang
- G Cheng
- X Yu
- H He
- G Cao
- H Lu
- Z Liu
- S.-Y Zheng
Wu, Z., Harrich, D., Li, Z., Hu, D., Li, D., 2020. Reviews in Medical Virology 31, e2171.
Xia, Y., Chen, Y., Tang, Y., Cheng, G., Yu, X., He, H., Cao, G., Lu, H., Liu, Z., Zheng, S.-Y., 2019.
ACS Sensors 4, 3298-3307.
Principles of bacterial detection: biosensors, recognition receptors and microsystems
- C Zhou
- X Zhang
- N Tang
- Y Fang
- H Zhang
- X Duan
- M Zourob
- S Elwary
- A P Turner
Zhou, C., Zhang, X., Tang, N., Fang, Y., Zhang, H., Duan, X., 2020. Nanotechnology 31, 125302.
Zourob, M., Elwary, S., Turner, A.P., 2008. Principles of bacterial detection: biosensors, recognition
receptors and microsystems. Springer Science & Business Media.