Enrique Valera

Enrique Valera
University of Illinois, Urbana-Champaign | UIUC · Department of Bioengineering

PhD
Research Assistant Professor

About

56
Publications
4,811
Reads
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1,010
Citations
Introduction
During the last 17 years I have researched several aspects of Bioengineering, especially focused on biosensors technology, point-of-care diagnosis, and microfluidics. In my current position at UIUC, I participate in several projects devoted to the detection of proteins and cells for sepsis stratification and to the development of 2D and 3D microfluidic cartridges for POC detection of pathogens from human samples, including SARS-CoV-2. I work in portable solutions for COVID-19 diagnosis.
Additional affiliations
July 2018 - present
University of Illinois, Urbana-Champaign
Position
  • Researcher
October 2016 - July 2018
University of Illinois, Urbana-Champaign
Position
  • Researcher
July 2016 - September 2016
University of Michigan
Position
  • Research Associate
Education
August 2004 - September 2008
Universitat Politècnica de Catalunya
Field of study
  • Electronic Engineering
February 2002 - May 2003
Universitat Politècnica de Catalunya
Field of study
  • Electronic Engineering
February 1996 - July 2003
Pontifical Catholic University of Peru
Field of study
  • Electronic Engineering

Publications

Publications (56)
Article
Objectives: We report the development of an optical immunosensor for the detection of monocyte chemotactic protein 1 (MCP-1) in serum samples. MCP-1 is a cytokine that is an emerging biomarker for several diseases/disorders, including ischemic cardiomyopathy, fibromyalgia, and some cancers. Design and Methods: The detection of MCP-1 was achieved b...
Article
Rapid, low-cost, and multiplexed biomolecule detection is an important goal in the development of effective molecular diagnostics. Our recent work has demonstrated a microfluidic biochip device that can electrically quantitate a protein target with high sensitivity. This platform detects and quantifies a target analyte by counting and capturing mic...
Article
Full-text available
Point-of-care (POC) detection technologies that enable decentralized, rapid, sensitive, low-cost diagnostics of COVID-19 infection are urgently needed around the world. With many technologies approved for commercialization in the past 10 months, the field of COVID-19 POC diagnostics is rapidly evolving. In this Perspective, we analyze the current s...
Article
Full-text available
Since the beginning of the COVID-19 pandemic, several mutations of the SARS-CoV-2 virus have emerged. Current gold standard detection methods for detecting the virus and its variants are based on...
Article
Rapid, simple, inexpensive, accurate and sensitive point-of-care (POC) detection of viral pathogens in bodily fluids is a vital component of controlling the spread of infectious diseases. The predominant laboratory-based methods for sample processing and nucleic acid detection face limitations that prevent them from gaining wide adoption for POC ap...
Article
Full-text available
In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other...
Article
The COVID-19 pandemic revealed fundamental limitations in the current model for infectious disease diagnosis and serology, based upon complex assay workflows, laboratory-based instrumentation, and expensive materials for managing samples and reagents. The lengthy time delays required to obtain test results, the high cost of gold-standard PCR tests,...
Article
The rapid and unexpected spread of SARS-CoV-2 worldwide has caused unprecedented disruption to daily life and has brought forward critical challenges for public health. The disease was the largest cause of death in the United States in early 2021. Likewise, the COVID-19 pandemic has highlighted the need for rapid and accurate diagnoses at scales la...
Article
Spatial mapping of heterogeneity in gene expression in cancer tissues can improve our understanding of cancers and help in the rapid detection of cancers with high accuracy and reliability. Significant advancements have been made in recent years in OMICS technologies, which possess the strong potential to be applied in the spatial mapping of biopsy...
Article
Full-text available
Efforts to mitigate the COVID-19 crisis revealed that fast, accurate, and scalable testing is crucial for curbing the current impact and that of future pandemics. We propose an optical method for directly imaging unlabeled viral particles and using deep learning for detection and classification. An ultrasensitive interferometric method was used to...
Preprint
In the Fall of 2020, many universities saw extensive transmission of SARS-CoV-2 among their populations, threatening the health of students, faculty and staff, the viability of in-person instruction, and the health of surrounding communities.1, 2 Here we report that a multimodal “SHIELD: Target, Test, and Tell” program mitigated the spread of SARS-...
Article
Full-text available
The COVID-19 pandemic has underscored the shortcomings in the deployment of state-of-the-art diagnostics platforms. Although several polymerase chain reaction (PCR)-based techniques have been rapidly developed to meet the growing testing needs, such techniques often need samples collected through a swab, the use of RNA extraction kits, and expensiv...
Article
Full-text available
Sepsis is a major cause of mortality among hospitalized patients worldwide. Shorter time to administration of broad‐spectrum antibiotics is associated with improved outcomes, but early recognition of sepsis remains a major challenge. In a two‐center cohort study with prospective sample collection from 1400 adult patients in emergency departments su...
Preprint
Efforts to mitigate the COVID-19 crisis revealed that fast, accurate, and scalable testing is crucial for curbing the current impact and that of future pandemics. We propose an optical method for directly imaging unlabeled viral particles and using deep learning for detection and classification. An ultrasensitive interferometric method was used to...
Preprint
Full-text available
The COVID-19 pandemic has underscored the shortcomings in the deployment of state-of-the-art diagnostic platforms. Although several PCR-based techniques have been rapidly developed to meet the growing testing needs, such techniques often need samples collected through a swab, the use of RNA extraction kits, and expensive thermocyclers in order to s...
Article
Full-text available
Significance An important limitation of current assays for the detection of SARS-CoV-2 stems from their reliance on time-consuming, labor-intensive, and laboratory-based protocols for viral isolation, lysis, and removal of inhibiting materials. While RT-PCR remains the gold standard for performing clinical diagnostics to amplify the RNA sequences,...
Preprint
Full-text available
The COVID-19 pandemic provides an urgent example where a gap exists between availability of state-of-the-art diagnostics and current needs. As assay details and primer sequences become widely known, many laboratories could perform diagnostic tests using methods such as RT-PCR or isothermal RT-LAMP amplification. A key advantage of RT-LAMP based app...
Article
Full-text available
Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response, leads the U.S in both mortality rate and cost of treatment. Sepsis treatment protocols currently rely on broad and non-specific parameters like heart and respiration rate, and temperature; however, studies show that biomarkers Interlukin-6 (IL-6) and Procalcitonin...
Article
Sepsis, a life-threatening syndrome that contributes to millions of deaths annually worldwide, represents a moral and economic burden to the healthcare system. Although no single, or even a combination of...
Article
Latent tuberculosis infection (LTBI) is estimated in nearly one quarter of the world’s population, and of those immunocompetent and infected ~10% will proceed to active tuberculosis (TB). Current diagnostics cannot definitively identify LTBI and provide no insight into reactivation risk, thereby defining an unmet diagnostic challenge of incredible...
Article
Deoxynivalenol (DON) is a toxic secondary metabolite produced by several species of Fusarium fungi, which can be predominantly found in agricultural crops such as wheat. In livestock, deoxynivalenol-contaminated grain can produce vomiting, feed refusal, weight loss, and diarrhea. This paper reports an electrochemical immunosensor for the detection...
Article
Sepsis, an adverse auto-immune response to an infection often causing life-threatening complications, results in the highest mortality and treatment cost of any illness in US hospitals. Several immune biomarker levels, including Interleukin 6 (IL-6), have shown a high correlation to the onset and progression of sepsis. Currently, no technology diag...
Article
A microfluidic device for assaying neutrophil motility in blood samples from sepsis patients and a machine-learning algorithm trained with the motility data enable a faster and accurate sepsis diagnosis.
Article
Full-text available
Antigen expression is an important biomarker for cell analysis and disease diagnosis. Traditionally, antigen expression is measured using a flow cytometer which, due to its cost and labor intensive sample preparation, is unsuitable to be used at the point-of-care. Therefore, an automatic, miniaturized assay which can measure antigen expression in t...
Article
As it is well known, electrochemical biosensors offer several very interesting advantages such as portability, low power consumption, low price, etc. However, in most of the cases these types of biosensors are weak in the simultaneous multiplexing detection. In general, these techniques are developed for single analyte detection, and when multiplex...
Article
A method for directly probing binding interactions in free solution, without the need for chemical tagging, offers exciting opportunities for non-perturbative analyses of biomolecules in their native state.
Article
Magnetic actuation has been introduced to an optical immunosensor technology resulting in improvements in both rapidity and limit of detection for an assay quantitating low concentrations of a representative protein biomarker. For purposes of demonstration, an assay was designed for monocyte chemotactic protein 1 (MCP-1), a small cytokine which reg...
Presentation
Biosensors play an important role in the biomedical research, drug and therapy discovery and health care. Two of the main application fields are in the personalized therapeutics for adjust the therapeutic agents dose (i.e. the glucose sensor for insulin dependent diabetes) and in point of care testing (POCT) devices. The main objective in this work...
Article
A magnetic interdigitated microelectrode (m-IDμE) has been developed, characterized and evaluated. In order to demonstrate the potential use of these electrodes in the biosensors field, impedimetric measurements of bovine serum albumin (BSA) biofunctionalized magnetic μ-particles (BSAMP) were performed. Thanks to their magnetic capabilities and to...
Article
A new electrochemical immunosensor has been developed to detect paraquat (PQ) pesticide residues in food samples. The immunosensor presented uses electrochemical nanoprobes prepared by labelling the PQ specific antibodies with CdS nanoparticles (CdSNP) and antigen biofunctionalized magnetic μ-particles. Electrochemical measurements are performed us...
Chapter
With the ever-increasing use of pharmaceuticals and the subsequent release into the environment comes the need for reliable detection methods. While the emphasis continues to be on chromatographic methods, every time, there are more and more biologically based assays being developed for the detection of pharmaceuticals in the environment. This chap...
Article
An electrochemical magneto immunosensor for the detection of low concentrations of paraquat (PQ) in food samples has been developed and its performance evaluated in a complex sample such as potato extracts. The immunosensor presented uses immunoreagents specifically developed for the recognition of paraquat, a magnetic graphite-epoxy composite (m-G...
Article
A new electrochemical immunosensor has been developed to detect sulfonamide antibiotic residues in food samples. The immunosensor presented uses immunoreagents specifically developed for the broad recognition of the sulfonamide antibiotic family, a graphite composite electrode (GEC), biofunctionalized magnetic μ-particles and electrochemical nanopr...
Article
The availability of pharmaceuticals to treat and to prevent disease has brought great benefit. Nevertheless, attention is being drawn to the uncontrolled use and careless disposal of medications for humans and animals. These compounds and their metabolites are found in the environment and foodstuffs, with possible adverse risks to human health. Det...
Article
The potential of a conductimetric immunosensor to detect residual amounts of atrazine in a complex matrix, such as red wine, is evaluated. The immunosensor presented is based on interdigitated μ-electrodes (IDμEs), immunoreagents specifically developed to detect atrazine, and antibodies labelled with gold nanoparticles. Due to the amplification of...
Article
The present paper describes a simple and low-cost method for the fabrication of mechanically flexible interdigitated μ-electrodes (FIDμEs) and its application as immunosensor. FIDμEs consist of two coplanar non-passivated interdigitated metallic μ-electrodes supported on a flexible transparent substrate, polyethylene naphthalate (PEN). Bioreagents...
Article
A novel conductimetric immunosensor for atrazine detection has been designed and developed. This immunosensor is mainly based on antibodies labelled with gold nanoparticles. Additionally, the immunosensor consists of an array of two coplanar non-passivated interdigitated metallic μ-electrodes (IDμE) and immunoreagents specifically developed to dete...
Article
A novel impedimetric immunosensor for atrazine detection has been developed. The immunosensor is based on an array of interdigitated micro-electrodes (IDmicroE) and immunoreagents specifically developed to detect this pesticide. Immunochemical determination of atrazine is possible without the use of any label. An atrazine-haptenized protein was cov...
Article
A novel impedimetric immunosensor for the detection of a wide variety of compounds, based on a two coplanar non-passivated interdigitated metallic μ-electrodes and non-labeled immunoreactives, has been designed and developed. A very useful detection method is the impedance spectroscopy sweeping a wide frequency range. This is a powerful, but cumber...
Article
Full-text available
Steady-state and transient conductance measurements of gold nanobeads solutions deposited on top of interdigitated electrodes have been performed. It is shown that the application of an electric field of moderate value between electrodes during the drying process of the droplet makes the resulting steady-state conductance value to increase signific...
Article
Full-text available
Steady-state and transient conductance measurements of gold nanobeads solutions deposited on top of interdigitated electrodes have been performed. It is shown that the application of an electric field of moderate value between electrodes during the drying process of the droplet makes the resulting steady-state conductance value to increase signific...
Article
Regular structures of SiO2 microneedles and Si micromonoliths have been formed using processing methods similar to those used in the microelectronics field; then these structures have been used as supports for zeolite (silicalite) films, grown on them by means of seeded hydrothermal synthesis. The procedure leads to microstructured nanoporous coati...
Article
Full-text available
This contribution describes the development of an impedimetric immunosensor for atrazine detection. This immunosensor is based on the use of interdigitated metallic μ-electrodes (IDμEs) The method described in this work does not use any redox mediator and relies on the direct detection of immunochemical competitive reaction between the pesticide an...
Article
A novel impedimetric immunosensor for atrazine detection, a widely used pesticide, is described. It is based on a two coplanar non-passivated interdigitated metallic μ-electrodes (IDμE) and the differential measurement of the impedance frequency spectrum. No redox electrodes have been included in the sensor. The chemical recognition layer was depos...
Conference Paper
A novel impedimetric biosensor for detection of a wide variety of compounds has been designed and developed. The biosensor is based on a non-isolated surface and non-labelled immunoreactives. The chemical recognition layer was deposited on the surface of the interdigitated mu-electrodes (IDmuE's) area (fingers and inter-digits space). Typically, th...
Article
A novel impedimetric immunosensor for atrazine detection, a widely used pesticide, is described. It is based on a two coplanar non-passivated interdigitated metallic μ-electrodes (IDμE) and the differential measurement of the impedance frequency spectrum. No redox electrodes have been included in the sensor. The chemical recognition layer was dep...
Conference Paper
A mu-porous silicon (muPS) gas sensor based on interdigitated mu-electrodes (IDmuE's) has been designed and developed. muPS obtained by means of electrochemical anodization of a p-type silicon (c-Si) wafer was used as active layer. The muPS layers are supported by the bulk of the c-Si wafer. Interdigitated mu-electrodes, which work as transducers,...
Article
This paper presents a novel technique for silicon dioxide (SiO2) microneedle fabrication. Microneedles are hollow microcapillaries with tip diameters in the range of micrometers. They can be used in the fabrication of microsyringes. These structures can be of high interest in medical and biological applications, such as DNA injection, antibody mani...
Conference Paper
Full-text available
The use of selectively formed microporous silicon as a sacrificial layer in silicon micromachining has been studied. Porous silicon formation, by isotropic etching in hydrofluoric acid (HF) can be selective, by creating n-type areas on a p-type substrate, or also, using polycrystalline silicon under adequate conditions. Porous silicon can be remove...
Conference Paper
Full-text available
This work presents a novel injection system based on silicon oxide microneedles. Microneedles fabricated in this work are hollow microcapillaries whose length ranges from tens to hundreds of microns and their tip diameter is in the range of micrometers. Structures based on microneedles are of increasing interest in medical and biological applicatio...
Conference Paper
In this paper we present a method for developing thick layers of silicon oxide. This work is divided into two parts. First we present the fabrication of the dielectric layer using porous silicon technology. In the second part we show the characterization of coplanar transmission lines deposited on it. In order to form the oxide layer, an electroche...

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