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a-k Functional groups with high affinity to the surfaces of NPs. a Thioesters, b thiols, c dithiocarbamates, d thioureas, e phosphine oxides, f amines, g phosphates, h catechins, i trimethoxysilane, j carboxylic acids, k alcohols
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Nanomaterials have revolutionized the sensing and biosensing fields, with the development of more sensitive and selective devices for multiple applications. Gold, silver and iron oxide nanoparticles have played a particularly major role in this development. In this review, we provide a general overview of the synthesis and characteristics of gold,...
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... In its nanoscale shape, a material has interesting electrical, optical and magnetic characteristics, which these properties cannot be discovered in bulk. This phenomenon can be explained using the "quantum size effect" [14][15][16] . In contrast to the nanoscale which there is an impact of specific individual atoms or molecules, on the bulk form, their properties are associated with the effect of all atoms due to the average of all the quantum forces. ...
The synthesis of magnetite (Fe3O4) nanoparticles with the addition of polyethylene glycol-4000 (PEG-4000) was successfully carried out using a two-step co-precipitation method for the possible biosensor applications. In this study, different concentrations of PEG on Fe3O4/PEG (1:0, 4:1, 3:1, 2:1 and 1:1) were used. The crystallite size of the Fe3O4 decreased (14.35 to 12.83 nm) with the increase of PEG concentrations. The presence of a new carbonyl group in the samples indicates the presence of PEG in the Fe3O4. The weight loss percentage of the Fe3O4 increased from 7.7 to 41.46 % with the increase of PEG concentrations. With the addition of PEG, Fe3O4 have a well-defined and homogeneous shape due to the presence of PEG which acts as a dispersing and stabilizing agent characterized. The magnetic properties showed that all samples exhibited superparamagnetic behavior. The saturation magnetization values of Fe3O4 decreased with increasing PEG layer and reached values of 65.34 emu/g with zero remanent magnetization and coercivity field while maintaining the behavior superparamagnetism and high saturation magnetization. To evaluate the magnetic properties of the samples to the sensitivity of biosensor, GMR-biosensor was used. Five types of Fe3O4/PEG-alcohol solutions with a concentration of 50 g/mL were dropped on the surface of the sensor. It was found that there was a decrease in the |∆ | value with the increase of PEG concentrations, undergoing a linear function |∆ | = 97.31 + 1880.97. Thus, the remarkable fact of saturation magnetization and controllable particle size in these Fe3O4/PEG can serve as promising biosensor applications.
... Noble metal nanomaterials like gold (Au), silver (Ag), palladium (Pd), platinum (Pt) consistent core-shell NPs, and bi-or tri-metallic alloys have been broadly amalgamated with bio-recognition units for monitoring of various targets in terms of their exclusive electronic, physical and chemical properties. Besides, outstanding catalytic and conductive attributes make them "electronic wires" while increasing etransfer between the redox centers in the surface of protein and electrodes [119,120,170]. Until now, nanoprobes based on noble metals/EG-SAMs as an antifouling reagent provided a high potential for improvement of both sensitivity and selectivity by increasing the tuned signal. ...
The ability to design nanoprobe devices with the capability of quantitative/qualitative operation in complex media will probably underpin the main upcoming progress in healthcare research and development. However, the biomolecules abundances in real samples can considerably alter the interface performance, where unwanted adsorption/adhesion can block signal response and significantly decrease the specificity of the assay. Herein, this review firstly offers a brief outline of several significances of fabricating high-sensitivity and low-background interfaces to adjust various targets' behaviors induced via bioactive molecules on the surface. Besides, some important strategies to resist non-specific protein adsorption and cell adhesion, followed by imperative categories of antifouling reagents utilized in the construction of high-performance solid sensory interfaces, are discussed. The next section specifically highlights the various nanocomposite probes based on antifouling-nanomaterials for electrode modification containing carbon nanomaterials, noble metal nanoparticles, magnetic nanoparticles, polymer, and silicon-based materials in terms of nanoparticles, rods, or porous materials through optical or chemical strategies. We specially outline those nanoprobes that are capable of identification in complex media or those using new constructions/methods. Finally, the necessity and requirements for future advances in this emerging field are also presented, followed by opportunities and challenges.
... In its nanoscale shape, a material has interesting electrical, optical and magnetic characteristics, which these properties cannot be discovered in bulk. This phenomenon can be explained using the "quantum size effect" [14][15][16] . In contrast to the nanoscale which there is an impact of specific individual atoms or molecules, on the bulk form, their properties are associated with the effect of all atoms due to the average of all the quantum forces. ...
The rapid advancement in the extraction method of metallic oxide nanoparticles from agricultural waste has led to the significant use of agriculture waste in the nanotechnology industry because the use of chemical procedures in the production of metallic oxide nanoparticles produces hazardous toxic compounds that are dangerous to the ecosystem. In particular, this article examines the creation of silicon dioxide (silica) nanoparticles from agricultural waste. Environmental cleanup and wastewater purification are only two examples of the many areas where sand-sized silica particles (SNPs) have shown promising results. rural, agricultural, etc. The lack of toxicity of these particles has been demonstrated, making them an excellent tool for biomedical study. Additionally, because of the particles' ability to mobilize molecules onto their interior and external surfaces, they constitute good transporters for both biotic and non-biotic substances. In this regard, the current paper provides a thorough assessment of the sources of agricultural waste used in producing silica nanoparticles as well as the processes used to create it. The report also examines SNPs' most recent applications in a number of fields and discusses the technology's potential for the future. Keywords: Fuel additives ; ethanol ; brake power ; Internal combustion engine ; fuel
First time we approached green way method to synthesize iron oxide (Fe3O4) nanoparticles using aqueous extract of Artocarpus heterophyllus seeds through an environmentally friendly method. Further, as prepared Fe3O4 nanoparticles were characterized and confirmed by different analytical techniques such as Fourier transform infrared (FT-IR) spectroscopy, Raman spectrum, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometer (EDAX) employed to determine the functional groups, crystalline structure, size, and shape of nanoparticles. A spherical with a size of 34 nm, and highly stable iron oxide nanoparticles were obtained. Further, Fe3O4 nanoparticles have been coated on the magnetic glassy carbon electrode (Fe3O4/MGCE) and applied for the electrocatalytic oxidation of carbofuran (CF) was examined by using cyclic voltammetry (CV) and differential pulse voltammetric (DPV) techniques. The Fe3O4/MGCE has shown excellent catalytic activity towards CF oxidation in the concentration of 0.3 – 38.5 µM with LOD of 0.01 µM and sensitivity of 6.53±0.08 µA µM⁻¹ cm⁻². Moreover, the practical applicability of the fabricated Fe3O4/MGCE has been applied for the detection of CF in different vegetable samples and the obtained results were compared with HPLC outputs.
Assessment of human epidermal growth factor receptor-2 (HER2) tumor marker status is an impressive factor in screening, diagnosing and monitoring breast cancer (BC). The electrochemical biosensor is a revolutionary method in cancer diagnosis, which is used in this research to detect HER2+ circulating tumor cells. The electrochemical activity, size, shape, and morphology of the synthesized nanomaterials were analyzed. The hybrid nanocomposite established by the coupling of reduced graphene oxide nanosheets (rGONs) and rhodium nanoparticles (Rh-NPs) on the surface of graphite electrode resulted in improved surface area, electrochemical activity, and biocompatibility. The graphite electrode-based aptasensor (g-aptasensor) demonstrated exceptional performance against HER2-overexpressed SKBR3 cancer cells, with a linear dynamic range of 5.0 to 10.0 × 104 cells/mL, an analytical limit of detection (LOD) as low as 1.0 cell/mL, and a limit of quantification (LOQ) of 3.0 cells/mL. The G-rich DNA aptamers can fold into an intermolecular G-quadruplex, which specifically bind to the target molecule. Consequently, the advantages of this highly efficient nanocomposite platform include broad dynamic range, high specificity, selectivity, stability, reproducibility, and low cost. These characteristics indicate that the fabricated nanobiosensor has a high potential for use in detecting and monitoring HER2 level for the care of BC patients and clinical diagnosis.
