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The successful development of biosensors is a result of a combination of technological achievements from various disciplines. A prerequisite for the creation of a successful biosensor is the placement of the biomolecules in specific locations with high resolution, on the sensor substrate, and the immobilization of the biomolecules with techniques that are able to ensure the bioactivity of the biomaterials while at the same time guarantee their attachment to the sensor surface for a desirable period of time. Furthermore, the future of biosensors depicts the need of development of new generation of biosensors with improved performance, increased sensitivity and selectivity while being able to monitor the results in real time and detect multiple analytes with the same sensor simultaneously. To satisfy those high expectations, the scientific community develops techniques to improve the electronic part and the signal of the biosensor device while also various techniques are investigated for the digital printing and functionalization of the sensor surface with the bio materials. To this end, this review tutorial focuses on direct write bioprinting techniques that have been used extensively for the printing of the biomaterials on various type of surfaces including sensor devices. We review the recent advancements of the techniques, in the field of biosensor development and explore their potential to be used for the creation of an all printed device rather than techniques used only for spotting biomaterials. Such advancements are expected to expand the biosensor availability and lower the cost while having a high impact to multiple disciplines.

We present BioChemPen, a portable wireless biosensor device for rapid analysis of substances adsorbed on solid surfaces. The device takes advantage of (bio)luminescent reactions taking place in a hydrogel matrix. In a typical embodiment, the active element of this device is a hydrogel disk (chemotransducer) containing enzyme(s), electrolyte solution, and all of the necessary substrates. When the hydrogel is exposed to a solid sample surface containing the target analyte, light is produced. A photoresistor (phototransducer), placed in close proximity to the hydrogel disk, detects the light. The operation of the BioChemPen is enabled by a MicroPython PyBoard microcontroller board and other low-cost electronic modules. The obtained results are immediately uploaded to the Internet cloud. In one application, we demonstrate an analysis of hypochlorite-containing cleaning agents present on the surfaces of daily use objects by an assay based on hydrogel embedded with luminol and hydrogen peroxide. In another application, we use hydrogel embedded with luciferin, luciferase, and pyruvate kinase to detect adenosine triphosphate (ATP), and adenosine diphosphate (ADP), and link the ATP content with meat freshness. Lastly, we demonstrate the detection of organophosphate pesticides present on vegetables with the hydrogel containing acetylcholinesterase, choline oxidase, and horseradish peroxidase. The limits of detection for sodium hypochlorite, ATP, ADP, and chlorpyrifos-methyl (a pesticide) were 7.95 × 10-11, 2.73 × 10-13, 2.35 × 10-12, and 2.59 × 10-10 mol mm-2, respectively.

Bioskins possess a great ability to detect and deliver external mechanical or temperature stimuli into identifiable signals such as color changes. However, the integration of visualization with simultaneous detection of multiple complex external stimuli in a single biosensor device remains a challenge. Here we propose an all-solution-processed bioinspired stretchable electronic skin with interactive color changes and four-mode sensing properties. The fabricated biosensor demonstrates sensitive responses to various stimuli including pressure, strain, voltage, and temperature. Sensing visualization is realized by color changes of the e-skin from brown to green and finally bright yellow as a response to intensified external stimuli, suggesting great application potential in military defense, healthcare monitoring, and smart bionic skin.

Inkjet printing technology holds a great potential for fabrication of biosensor device. An optimized programmed printing makes the processing steps easier on a variety of substrates at low cost. The drop-on-demand piezoelectric mode of printing can construct a design pattern with low volume of material at specified position onto a suitable substrate. But to achieve this successfully, a formation of stable ink suspension remains the most challenging task. In recent times, nanoparticles are considered to pave a way for miniaturization of biosensing devices. Thus, we synthesized, characterized and investigated the stability of magnetic Fe3O4 nanoparticles stabilized by the polyamidoamine (PAMAM = N(CH2CH2C(O)NHCH2CH2NH2)(CH2CH2N(CH2CH2C(O)NHCH2CH2NH2)2)2) dendrimer (PAMAM@Fe3O4). A best stable ink dispersion of PAMAM@Fe3O4 nanoparticles was obtained in a solvent mixture of 70% ethylene glycol and 30% distilled water. The nanoparticle ink with surface tension of 57.47 mN/m and viscosity of 5.45 mPa/s formed a narrow and uniform printed pattern onto graphene paper. Further, as a model protein for future biosensing application, antibody against alpha-fetoprotein was conjugated onto the dendritic surface and printed onto graphene paper. The characterization of the printed pattern by TEM revealed spherical morphology, whereas SEM provided evidence of difference in printed line width and spacing of nanoparticles and antibody conjugated nanoparticles. As a proof-of-concept, the study demonstrated a printable ink dispersion based on PAMAM@Fe3O4 nanoparticles for future miniaturization of biosensing steps on a chip-based platform.

In this paper, for the first time, a unique pTFET-based biosensor device having channel epilayer has been introduced and its performance in the sensing domain has been studied in terms of five different sensitivity parameters. A rigorous analysis of the effect of the existent corner point (corner-effect) in the proposed device architecture on the sensitivity metrics has been performed for five different channel epilayer thicknesses, covering five different types of protein-molecules, viz., Apomyoglobin, Myoglobin, Protein-G, Ferricytochrome-C, and Ferrocytochrome-C. This is followed by determining detectability and optimum length-window of nanogap cavity of the proposed sensor device for the successful detection. Interestingly, it has been found that the undesired corner-effect, generally known for its unfavorable impact on the electrical behaviors of the MOS-based structures, actually comes to the aid by enhancing the detectability of the proposed device compared to its equivalent conventional SOI pTFET sensor device by almost 67% (for Protein-G, Ferricytochrome-C, and Ferrocytochrome-C) and 50% (for Apomyoglobin and Myoglobin) yet maintaining significantly good values for the sensitivity metrics throughout. Furthermore, smaller epilayer thicknesses ensure smaller optimum length-window of the nanogap cavity, resulting in more scaled-down device, compared to larger epilayer thickness values. A position-dependent variability study for the detectability also follows, and it has been found that for small epilayer thicknesses this dependency becomes large leading to less stable device, although, at the same time producing higher sensitivity metrics compared to the devices having large epilayer thicknesses. This makes the choice of channel epilayer thickness as application-specific.

In this study, the extended-gate field-effect transistor (EGFET) with an on-chip sensing window under the TSMC $0.18{\mu }\text{m}$ 1P6M (one poly and six metals) CMOS process technology was fabricated as a biosensor. The sensing window was composed of six metal layers and functionalized with the ruthenium dioxide (RuO2) thin film and uricase for uric acid detection. The RuO2 thin film was deposited on the top metal layer of the sensing window using the radio frequency (RF) sputtering system. The silver probe was employed as a reference electrode to provide a voltage to the test solution with a micro-volume of $0.5 {\mu }\text{L}$ . The properties of the EGFET for uric acid detection were investigated through the semiconductor parameter analyzer. The EGFET had a voltage and the current sensitivity of 8.63 mV/(mg/dL) and 0.17 ( ${\mu }\text{A}$ ) $^{1/2}$ /(mg/dL), respectively. The device worked with a supply voltage lower than 1.8V. Based on the results, the fabrication of the miniaturized biosensor device was a success. Due to its advantages such as the use of low voltage and its simple fabrication process, it could help realize the development of a wearable biosensor.

Known as a main neural MAP (microtubule associated protein), tau protein contributes to stabilizing microtubules involved in cellular transmission. Tau dysfunction is mainly associated with neurodegenerative diseases, particularly Alzheimer's disease (AD). In these patients, all the six tau isoforms, which are in hyperphosphorylated form, are first aggregated and then polymerized into neurofibrillary tangles inside the brain. Tau protein detected in cerebrospinal fluid (CSF) is significantly correlated with AD and is well recognized as a hallmark of the disease. Served for detection of analytes of interest, biosensor device comprises a physical transducer and a keen biological recognition component. Qualitative and quantitative evaluations may be performed through analyzation of the data, which is gathered by measurable signals converted from biological reaction. Antibodies, receptors, microorganisms, nucleic acids, enzymes, cells and tissues, as well as some biomimetic structures, normally constitute the biosensor biological recognition part. Production of nanobiosensor, which was made possible through several accomplishments in nano- and fabrication technology, opens up new biotechnological horizons in diagnosis of multiple diseases. In recent years, many researches have been focused on developing novel and effective tau protein biosensors for rapid and accurate detection of AD. In this review, tau protein function and correlation with AD as well as the eminent research on developing nanobiosensor based on optical, electrochemical and piezoelectric approaches will be highlighted.

It is important that biosensor surface chemistry assays because of the easy immobilization of biological sensing molecules on the chip surface and especially not damage of these molecules through surface effects. Boronic acid modified self-assembled monolayers can be formed on gold electrodes and used immobilizations of glycoproteins. Glycoproteins which have short oligosaccharides exist in various cellular events with different functions and serve in many cellular events as cell surface recognition. It was successfully fabricated a new phenylboronic acid self-assembled layer on gold electrodes for immobilization of glycoproteins, where 4-aminophenylboronic acid (APBA) is covalently bound to the 11-mercapto-1-undecanol (MUOL) layer with glutaraldehyde linkage. The specific binding of glycoprotein with self-assebled layer was studied using horseradish peroxidase (HRP) as a model protein. All the experiments, voltametric and amperometric measurements were carried out during microfluidic flow first time using automated new biosensor device that enabled fast and easy modification of electrode surface with boronic acid and immobilization of the HRP protein in a short period of time.

The antibody immobilization compatible with low-cost materials and label-free strategies is a challenge for biosensor device fabrication. In this study, ZnO thin film deposition was carried out on ...

Bladder cancer (BC) is the fourth most common malignant tumor in the United States. It is the second most common cancer of the urinary system, accounting for 7% of all new cancer cases. It is also the fifth deadliest cancer, accounting for 4% of all cancer-related deaths in the United States. Our efforts to reduce costs of BC diagnosis and improve patients’ quality of life by avoiding unnecessary invasive diagnostic tests resulted in findings of promising urinary biomarkers for the detection of BC. This short review article aims to provide the current status of non-invasive biosensor device development for detection of BC, in particular, in patients’ urine samples.

Rapid and low-cost diagnosis of COVID-19 is essential to identify the infected subjects, particularly the asymptomatic cases, primarily to arrest the spread of the disease through local transmission. Antibody-based chromatographic serological tests, as an alternative to RT-PCR, offer only limited help due to high false positives. We propose to exploit our field-deployable/portable plasmonic fiber-optic absorbance biosensor (P-FAB) platform for one-step, wash-free detection of SARS-CoV-2 virus particles directly in saliva sample with minimal sample pre-processing.

In this article, for the first time, the performance of a double-hetero-gated-dielectric-modulated tunnel FET (DHGDM-TFET) biosensor device, having channel length ( ${L}_{\text{ch}}$ ) of 50 nm, is thoroughly investigated in terms of threshold voltage- ( ${V}_{\text {TH}}$ -), subthreshold swing- (SS-), ON-current- ( ${I}_{ \mathrm{\scriptscriptstyle ON}}$ -), and OFF-current- ( ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ -) sensitivity parameters, in order to find its suitability in successful detection and identification of different biomolecules. The investigation is further extended to the optimization of the proposed sensor device, against cavity length ( ${L}_{\text {Cavity}}$ ) and misalignment effect between the cavity and high- ${k}$ dielectric, underneath the cavity of the sensor device. It is found that our proposed biosensor device works at its optimum with ${L}_{\text {Cavity}} =10$ nm, while the cavity is perfectly aligned with the underneath high- ${k}$ of the device. Furthermore, a comparison of our proposed device is performed against its equivalent high- ${k}$ only and SiO2 only TFET-based biosensors. For each aforementioned sensitivity parameter, it is found that our proposed DHGDM-TFET biosensor device outperforms the rest two devices, proving the superiority in sensing action.

Cancer is the uncontrolled growth of abnormal cells via malignant cell division and rapid DNA replication. While DNA damaging molecules can cause cancer, their role as anticancer drugs are very significant. For this purpose, the novel series of paraben substituted spermine bridged(dispirobino) cyclotriphosphazene compounds 2-6 were synthesized for the first time, and their structures were characterized by various spectroscopic techniques. The solid-state structures and geometries of compounds 2-6 were determined using single-crystal X-ray structural analysis. In addition, it was confirmed by TGA that all compounds 1-6 showed high thermal stability. Two methods were used in order to investigate DNA interaction properties of the targeted molecules. While biosensor-based screening test that measures DNA hybridization efficiency on a biochip surface, the agarose gel electrophoresis method examines the effect of compounds on plasmid DNA structure. The results collected from the automated biosensor device and agarose gel electrophoresis have indicated that compounds 1, 5, and 6 showed higher DNA damage than the compounds 2-4. According to the biosensor results, compounds 1, 5, and 6 showed 85%, 69%, and 77% activity, respectively.

The effect of partial hybridization and probe positioning on the performance of a label free biosensor has been investigated in this article. Dielectric modulated dual-metal double-gate oxide stacked junctionless MOSFET based biosensor device has been considered as a reference during analysis. Primarily, an optimized device dimension has been proposed based on device parameters, cavity positions, etc. Later, Sensitivity parameter variations in terms of threshold voltage (VTH) and drain current (IDS) have been investigated by considering partial hybridization (PH) and arrangement of receptor-biotarget pairs. Analytical modeling has been detailed to study the performance of the sensor. Extensive simulations using the SILVACO ATLAS investigate the effects. Mainly, irregular arrangements of biomolecules like an enzyme (Staphylococcal nuclease) and DNA (negatively-charged) are examined here. Also, the minimum detection limit of the biosensor has been addressed including a capacitive model. It was observed that the optimized cavity with dimension (400 nm × 10 nm) can accommodate almost 1.016 × 105 (∼ 17 aM) number of Myoglobin enzyme. Analysis of these practical issues during the label free detection of charged/neutral biomolecules with higher sensitivity would be efficacious to find out the promising alternative in biosensing applications.

A biosensor device for the detection and characterization of protein-glycosaminoglycan interactions is being actively sought and constitutes the key to identifying specific carbohydrate ligands, an important issue in glycoscience. Mass spectrometry (MS) hyphenated methods are promising approaches for carbohydrate enrichment and subsequent structural characterization. In the study herein, we report the analysis of interactions between the glycosaminoglycans (GAGs) heparin (HP) and heparan sulfate (HS) and various cytokines by coupling surface plasmon resonance imaging (SPRi) for thermodynamic analysis method and MALDI-TOF MS for structural determination. To do so, we developed an SPR biochip in a microarray format and functionalized it with a self-assembled monolayer of short poly(ethylene oxide) chains for grafting the human cytokines stromal cell-derived factor-1 (SDF-1α), monocyte chemotactic protein-1 (MCP-1), and interferon-γ. The thermodynamic parameters of the interactions between these cytokines and unfractionated HP/HS and derived oligosaccharides were successively determined using SPRi monitoring, and the identification of the captured carbohydrates was carried out directly on the biochip surface using MALDI-TOF MS, revealing cytokine preferential affinity for GAGs. The MS identification was enhanced by on-chip digestion of the cytokine-bound GAGs with heparinase, leading to the detection of oligosaccharides likely involved in the binding sequence of GAG ligands. Although several carbohydrate array-based assays have been reported, this study is the first report of the successful analysis of protein-GAG interactions using SPRi-MS coupling.

Here we demonstrate for the first time a dynamic monitoring of the ethanol metabolite Ethyl Glucuronide (EtG) for a more robust evaluation of alcohol consumption compared to conventional methods. A wearable biosensor device capable of reporting EtG levels in sweat both continuously via low power impedance spectroscopy is reported. The custom hardware was compared against conventional benchtop potentiostat, demonstrating comparable results in the application space of EtG detection in low volume sweat. The device successfully differentiated three distinct EtG concentrations correlating to simulated drinking scenarios estimated to be 1, 2, and 3 standard U.S. drinks consumed over a duration of 60 minutes with p < 0.0001. This device has the potential to enable moderate drinkers to engage in guided decision making, based on objective data, addressing the needs of alcohol sensitive populations. The device also will serve as a tool for researchers to better understand and characterize the relationship between sweat EtG and consumed alcohol.

Background : Research suggests optimizing sleep, exercise and work-life balance may improve resident physician burnout. Wearable biosensors may allow residents to detect and correct poor sleep and exercise habits before burnout develops. Our objectives were to evaluate the feasibility of a wearable biosensor to characterize exercise/sleep in neurology residents and examine its relationship to self-reported, validated survey measures. We also assessed the device's impact on well-being and barriers to use. Methods This prospective cohort study evaluated the WHOOP Strap 2.0 in neurology residents. Participants completed regular online surveys, including self-reported hours of sleep/exercise, and validated sleep/exercise scales at 3-month intervals. Autonomic, exercise, and sleep measures were obtained from WHOOP. Changes were evaluated over time via linear regression. Survey and WHOOP metrics were compared using Pearson correlations. Results Sixteen (72.7%) of 22 eligible participants enrolled. Eleven (68.8%) met the minimum usage requirement (6+ months) and were classified as "consecutive wearers". Significant increases were found in sleep duration and exercise intensity. Moderate-to-low correlations were found between survey responses and WHOOP measures. Most (73%) participants reported a positive impact on well-being. Barriers to use included "Forgetting to wear" (20%) and "not motivational" (23.3%). Conclusion Wearable biosensors may be a feasible tool to evaluate sleep/exercise in residents.

A microcantilever array chip made with Micro-Electro-Mechanical System (MEMS) technology has been demonstrated to develop as a biosensor device. This chip includes four gold-covered and embedded polysilicon wire with microfabricated Si beams. The polysilicon coat serves as a piezoresistor, and changes in resistance due to compressive and tensile forces indicate microcantilever deformation. The relationship between initial resistance and microcantilever deflection demonstrates that this device has a detection range of 0-56kΩ. The investigation of the microcantilever response to biotin immobilisation revealed that resistance change caused by Biotin absorption can be observed and reaches a degree of amount independence at Biotin concentrations higher than 80pg/ml. The results suggested that this device could be developed as a piezoresistive-based microcantilever biosensor.

Biosensors are sensing devices engineered to measure biological or chemical reactions by generating a response signal which is relative to the concentration of an analyte in the reaction. A general biosensor device is made up of five different components: an analyte, the bioreceptor, a transducer, the electronic and the display. When presented together, they form a sensing system that can be tailored to detect specific analytes. Energy conversion events controlled by engineered components within the biosensor molecule, take advantage of the specificity in binding to trigger measurable signals that can be later modified into digital form in order to be understandable. Previous studies done at the Alexandrov’s group have shown that it is possible to engineer allosterically regulated protein switches by domain insertion in order to design more integrated receptor/transducer architecture. This architecture is referred to as “the two-component biosensor”, and it is designed to incorporate ligand-binding domains of every nature in order to potentially have tailored-made biosensors for the most relevant biomarkers found in the blood. However, there is a need to test and select the incredible myriad of ligand-binding proteins present up to date. The work done here tackles a challenge in biosensor design where a potentially infinite arrange of combinations and alternatives can happen between the analyte and the bioreceptor module. This thesis describes the path towards a screening methodology for ligand-binding domains that could accelerate the development of new biosensors and, we show the complete design and testing of a new biosensor for a relevant human biomarker for coronary events. Given the ever-growing interest in biosensor research fuelled by the contemporary concern in human diagnostics and the rise of point-of-care analysis, technologies are extending their applications not only to the pharmaceutical industry, but also human health, environmental monitoring, food safety, forensics, and biomedical research

Skin-like electronics on human skin can be operated in real-time and in a non-invasive manner for ECG biosensors. Conductive hydrogels possessing high electrical conductivity, soft and moisturizing properties, have great potential in this field. Herein, we propose to use polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) as the skeleton of the hydrogel, the polyethylene-3,4-dioxythiophene:sodium polystyrene sulfonate (PEDOT:PSS) mixture is evenly dispersed among it to form a continuous and interconnected conductive pathway. The prepared conductive hydrogels have an electrical conductivity of 75 S m−1 with high water content (above 80 %) and mechanical properties, leading to sufficiently soft and moisturizing, and can take place of traditionally high-cost Ag/AgCl electrodes. Importantly, these conductive hydrogels are similar to human tissues and can form a naturally seamless interface between the human body and the ECG biosensor device, promoting the high response of obtained electronic signals with low impedance. Therefore, these functionalized conductive hydrogels show excellent application prospects in ECG biosensors.

Glycans (oligosaccharide chains attached to glycoproteins) are a promising class of biomarkers, found in body fluids such as serum, saliva, urine, etc., that can be used for the diagnosis of disease conditions. Subtle changes in glycans resulting from altered glycosylation machinery have been reported during various diseases, including carcinogenesis. In this article, we detail protocols for the rapid, label-free analysis of glycans using a previously developed highly sensitive and selective electrochemical impedance spectroscopy-based biosensing diagnostic platform called "NanoMonitor." The glycosensor operation is based on the specific affinity capture of the target glycans on the sensor surface by glycan-binding proteins known as lectins. This glycan-lectin binding activity modulates the impedance of the electrical double layer at the buffer-electrode interface. Protocols for the preparation of glycoprotein samples and glycosylation analysis using NanoMonitor and lectin-based ELISA are described here. The data obtained using these protocols show that NanoMonitor is capable of distinguishing between glycoform variants of the glycoprotein fetuin and glycoproteins derived from cultured human pancreatic cancer cells with high sensitivity (orders of magnitude higher than lectin-based ELISA) and selectivity. The results obtained indicate that NanoMonitor protocols can be further developed to enable use of NanoMonitor as a handheld electronic biosensor device for routine multiplexed detection of glycan biomarkers from clinical samples. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Preparing the NanoMonitor surface for glycan biosensing Support Protocol: Synthesis of glycoform variants of fetuin Basic Protocol 2: Performing Electrochemical Impedance Spectroscopy (EIS) for analyzing glycoprotein structures.

Performance analysis of a doping-less Z-shaped charge plasma tunnel field effect transistor-based (CP-TFET) label-free biosensor is done with misaligned cavity region on the source and channel. The biosensor device is designed using charge plasma technology. We use suitable metal work function to create source, channel, and drain regions. This device is used for label-free electrical identification of biomolecules such as, uricase (k=1.54), streptavidin (k=2.1), biotin (k=2.63), 3-aminopropyltriethoxysilane (APTES) (k=3.57), keratin (k=8), and gelatin (k=12). The results shows better sensitivity in terms of I ON , I OFF , sub-threshold swing (SS), ION/IOFF ratio as compared to FET-based biosensors. All simulations have been performed in the Silvaco ATLAS 2D device simulator.

The direct exploitation of generated hot charge carriers originating by localized surface plasmon resonance (LSPR) from a plasmonic metal nanostructure has been an important topic for enhancing the...

This review summarizes the development of whole-cell biosensors with a special focus on device development and cell immobilization. Integration of biosensor functions in a device will pave the way for field applications in remote areas and resource-limited settings. Firstly, an introduction to the field of whole-cell biosensors is provided, followed by examples of genetic engineering of cells in order to fulfill sensor functions. A framework of requirements to enable future field applications of biosensors is elaborated. A special focus is on different cell immobilization techniques ranging from polymers, to microfluidic devices, immobilization on paper and combinations of these methods. Looking at globally successfully implemented point of care devices such as a home pregnancy test or a blood glucose meter, we conclude the review with thoughts on long-term stability, portability, ease of use and user safety design guidelines for whole-cell biosensor devices.

Enzyme immobilization method in packaged freestanding microfluidic channel is developed for biomolecule assembly of biosensor in this research. A new micro fluidic fabrication method is proposed to fabricate freestanding fluidic structure by MEMS technology. The SU-8 polymer channel is treated by plasma treatment to change hydrophobic surface to hydrophilic property which can automatically drive the liquid into the channel by capillary force. The electro click chemistry method is carried out in hydrophilic SU-8 micro channel by capillary effect. The results show that enzyme immobilization can be immobilized by electro click chemistry in completely packaged freestanding channel. The proposed enzyme immobilization method in micro channel is capable of minimizing biosensor device for healthcare application.

Oxytetracycline (OTC) is a member of the broad-spectrum tetracycline (TC) group of antibiotics and TCs are widely used to prevent bacterial infections in livestock and increase their growth rate. Hence a large percentage of the antibiotics is either accumulated in tissues or excreted and released into the environment that leads to serious health implications such as antibiotic resistance. Thus, simple, fast and easy to use methods are needed for OTC detection. Here a simple and highly sensitive aptamer-based single walled carbon nanotube (SWCNT) biosensor containing probe-DNA immobilized on functionalized SWCNTs was developed for fast and specific OTC detection. We employed a newly developed flexible biosensor device which was fabricated by a high-rate nanoscale offset printing process using directed assembly and transfer of SWCNTs. Employing a simple directed assembly and non-covalent functionalization process these fabricated probe DNA-based SWCNT biosensors were designed with two electrode terminals to allow continuous resistance response monitoring for antibiotics detection. The developed environmental sensor had a detection range of 10 μg L−1 to 75 μg L−1 (20–325 nM), with a detection limit of 1.125 μg L−1 (2.5 nM). When compared to other biosensors such as colorimetric, electrical or cantilever-based biosensor systems, the biosensor developed here is simpler and faster (less than 10 minutes, including pre-incubation, measurement and regeneration) with a lower detection limit. And the portable platform also allows for potential on-site or real-time measurements. The biosensor could be regenerated and reused over 20 times with good stability with signal decrease less than 15%. In addition, its inherent miniature size makes this biosensor potentially useful for a simple portable model for environmental and industrial applications.

Background: Alzheimer’s disease (AD) is the most common and most costly chronic neurodegenerative disease globally. AD develops over an extended period prior to cognitive symptoms, leaving a “window of opportunity” for targeted risk-reduction interventions. Further, this pre-dementia phase includes early physiological changes in sleep and autonomic regulation, for which wearable biosensor devices may offer a convenient and cost-effective method to assess AD-risk. Methods: Patients with a family history of AD and no or minimal cognitive complaints were recruited from the Alzheimer’s Prevention Clinic at Weill Cornell Medicine & New York-Presbyterian. Of the 40 consecutive patients screened, 34 (85%) agreed to wear a wearable biosensor device (WHOOP). One subject (2.5%) lost the device prior to data collection. Of the remaining subjects, 24 were classified as normal cognition and were asymptomatic, 6 were classified as subjective cognitive decline, and 3 were amyloid-positive (one with pre-clinical AD, one with pre-clinical Lewy-Body Dementia, and one with mild cognitive impairment due to AD). Sleep-cycle, autonomic (heart rate variability [HRV]) and activity measures were collected via WHOOP. Blood biomarkers and neuropsychological testing sensitive to cognitive changes in pre-clinical AD were obtained. Participants completed surveys assessing their sleep-patterns, exercise habits, and attitudes towards WHOOP. The goal of this prospective observational study was to determine the feasibility of using a wrist-worn biosensor device in patients at-risk for AD dementia. Unsupervised machine learning was performed to first separate participants into distinct phenotypic groups using the multivariate biometric data. Additional statistical analyses were conducted to examine correlations between individual biometric measures and cognitive performance. Results: 27 (81.8%) participants completed the follow-up surveys. Twenty-four participants (88.9%) were satisfied with WHOOP after six months, and twenty-three (85.2%) wanted to continue wearing WHOOP. K-means clustering separated participants into two groups. Group 1 was older, had lower HRV, and spent more time in slow-wave sleep (SWS) than Group 2. Group 1 performed better on two cognitive tests assessing executive function: Flanker Inhibitory Attention/Control (FIAC) (p=.031), and Dimensional Change Card Sort (DCCS) (p=.061). In Group 1, DCCS was correlated with SWS (ρ=.68, p=0.024) and HRV (ρ=.6, p=0.019). In Group 2, DCCS was correlated with HRV (ρ=.55, p=0.018). There were no significant differences in blood biomarkers between the two groups. Conclusions: Wearable biosensor devices may be a feasible tool to assess AD-related physiological changes. Longitudinal collection of sleep and HRV data may potentially be a non-invasive method for monitoring cognitive changes related to pre-clinical AD. Further study is warranted in larger populations.

In this work, In2O3 electrolyte gated thin film transistors (In2O3-EGTFTs) with integrated on-chip gate electrode were investigated as a label-free biosensor. The In2O3 channel works as sensitive membrane and the on-chip gate electrode replaces reference electrode. The pH sensitivity of the device is 64 mV/pH with the deviation of 10 mV. The In2O3 channel was coated by streptavidin/neutravidin receptors to detect the target biomolecules of biotin. The streptavidin modified device presents an ultra-low working voltage ( $\text{V}_{\text{G}}=0$ V, $\text{V}_{\text{DS}}=50$ mV) and the detection limit as low as 50 pg $\cdot $ mL $^{-1}$ . And the neutravidin modified device presents apparent detecting performance even in low biotin concentration of 50 fg $\cdot $ mL $^{-1}$ under a working voltage of $\text{V}_{\text{G}}=2$ V and $\text{V}_{\text{DS}}=50$ mV. This work provides a high-performance biosensor device with low power consumption and simple structure that is easy to integrate and package.

A photoelectrochemical biosensing strategy for the highly sensitive detection of the flavonoid rutin was developed by synergizing the photoelectrocatalytic properties of hematite (α-Fe2O3) decorated with palladium nanoparticles (PdNPs) and the biocatalysis towards laccase-based reactions. The integration of α-Fe2O3.PdNPs with a polyphenol oxidase as a biorecognition element yields a novel biosensing platform. Under visible light irradiation, the photoactive biocomposite can generate a stable photocurrent, which was found to be directly dependent upon the concentration of rutin. Under the optimal experimental conditions, the cathodic photocurrent, measured at 0.33 V vs. Ag/AgCl, from the square-wave voltammograms presented a linear dependence on the rutin concentration within the range of 0.008–30.0 × 10−8 mol L−1 (sensitivity: 1.7 μA·(× 10−8 M−1)·cm−2), with an experimental detection limit (S/N = 3) of 8.4 × 10−11 mol L−1. The proposed biosensor device presented good selectivity towards rutin in the presence of various organic compounds and inorganic ions, demonstrating the potential application of this biosensing platform in complex matrices. This bioanalytical device also exhibited excellent operational and analytical properties, such as intra-day (standard deviation, SD = 0.21%) and inter-day (SD = 1.30%) repeatability, and long storage stability (SD = 2.80% over 30 days). Graphical abstract

In this paper, a triple metal gate high-k gate all around junctionless nanowire field-effect transistor biotin biosensor has been developed to study the impact of different interface trap charges (ITCs) on device performance. The output characteristics, such as transconductance, drain current, total current density, and threshold voltage of proposed device have been examined. All results were authenticated using ‘‘atlas-3D’’ device simulation tool. Effect of interface trap charge on output characteristics, such as transconductance, switching ratio, leakage current, and total current density, including air and biotin biomolecule, have been studied. Drain-off current ratio was considered as a sensing metric for biotin biomolecule detection with different interface trap charges (ITCs). For instance, drain-off current results of biotin biomolecule in the presence of interface trap charge are \({3.12 \times 10}^{-12}\,\mathrm{A}\), \({2.10 \times 10}^{-13}\,\mathrm{A}\) and \({4.07 \times 10}^{-16}\,\mathrm{A}\) for positive, neutral, and negative interface trap charges, respectively. Finally, we have found that a negative ITC has a positive impact on our proposed biotin biosensor device performance than the positive ITCs, proving its efficacy for the detection of cardiovascular diseases in biomedical applications.

In the paper, for the first time, a unique pTFET-based biosensor device having a channel epilayer (epi-pTFET-biosensor) has been introduced and its performance in the sensing domain has been studied through a rigorous analysis based on five different sensitivity parameters, followed by the determination of detectability of the proposed device and an optimum length-window of the nanogap cavity for the successful detection of five different types of bio-molecules, viz., Protein-G, Ferrocytochrome-C, Ferricytochrome-C, Myoglobin, and Apomyoglobin. Interestingly, it has been found that the undesired corner-effect, generally known for its detrimental impact on the subthreshold characteristics of the MOS-based structures, when generated by the presence of a corner due to the introduced epilayer, actually, comes to the aid of the proposed epi-pTFET-biosensor device by enhancing its detectability, compared to its equivalent conventional SOI pTFET sensor device by a great degree, yet maintaining significantly good sensitivity matrices throughout.

The distinction and characterization of noise have been carried out in the current mirror (CM) circuit as a part of a biosensor system with some main components of MOSFET type BS250 and two resistors at the input (Rref) and output (RL) of the circuit. This evaluation is important since the biosensor module has very high impedance due to the low conductivity sample measured and the high loading resistance for current to voltage conversion. This high impedance leads to the rise of high noise due to thermal noise which is proportional to the resistance, in addition, the type and the specifications of the MOSFET determine the noise due to semiconductor properties. Therefore, this evaluation can be used to reduce the resulted noise to obtain high Signal to Noise Ratio (SNR). The experiment was performed by applying Rref and RL with some values of 1 kν, 100 kν and 1 Mν while maintaining the voltage source at 1 V, which causes the input current to vary accordingly. This experiment was adjusted to meet the range of current in the biosensor application, which is relatively very small. The measurement is acquired by a DAQ card PCI-6221 that has been integrated with a LabVIEW program based on Fast Fourier Transform (FFT). The noise response analysis is performed within a bandwidth of 0.1 Hz to 100 kHz and a frequency resolution of 0.1 Hz. This bandwidth is sufficient to describe the noise in the CM circuit applied to the biosensor device. The results show that the noise characteristics vary with the applied resistance. Thus, it can be considered to determine an appropriate loading resistance, which could be used to build a high SNR current mirror circuit for the biosensor system.

This study develops an ultrasensitive electrical device, the silicon nanowire-field effect transistor (SiNW-FET) for detection of cardiac troponin I (cTnI) in obesity induced myocardial injury. The biosensor device utilizes metal–oxide–semiconductor (MOS) compatible top-down methodology for the fabrication process. After fabrication, the surface of the SiNW is modified with the cTnI monoclonal antibody (Mab-cTnI) upon covalent immobilization to capture cTnI antigen. The sensitivity of the device is also examined using cTnI at different concentrations with the lowest detection limit of 0.016 ng/mL. The electrocardiogram (ECG), magnetic resonance imaging (MRI), and superior vena cave (SVC) provide more information about cardiac responses in a mouse model of acute myocardial infarction (AMI). Further, magnetic resonance imaging helps to evaluate the cardiac output of an obesity induced myocardial injury mouse model. These methods play an essential role in monitoring the obesity based cardiac injury and hence, these studies were carried out. This is the first report to use the ECG, MRI, and SVC sampling methods to study the obesity based cardiac injury involving Syrian hamsters as animal models. The proposed SiNW-FET in this study shows greater sensitivity than the previously developed devices and demonstrates great potential for future applications in point-of-care (POC) diagnosis.

The present work reports an enhancement in early diagnosis of DNA of prostate cancer by a rapid and sensitive biosensor. The genosensor platform was designed and fabricated using cost‐effective and disposable paper‐based electrodes. Herein, the bio‐nano‐interface was developed by immobilization of probe DNA of prostate cancer on the zinc oxide tetrapods modified paper electrode. The genosensor was characterized by scanning electron microscopy, transmission electron microscopy, synchrotron X‐ray photoelectron spectroscopy, cyclic voltammetry and impedance spectroscopy. The nano‐engineered genosensor was tested and found to be selective to prostate cancer. The sensor could detect as low as 1 pM of prostate cancer DNA with the linear detection range from 50 µM to 1 pM. The paper‐based genosensor also proved to be advantageous in terms of easy preparation, low specimen volume, homogenous distribution of nanostructures onto the surface and cost‐effectiveness. The present work demonstrates the enormous potential of DNA biosensor as a rapid and specific diagnostic tool to be used for the detection of prostate cancer DNA.

Stroke is a top leading cause of death, which occurs due to interference in the blood flow of the brain. Ischemic stroke (blockage) accounts for most cases (87%) and is further subtyped into cardioembolic, atherosclerosis, lacunar, other causes, and cryptogenic strokes. The main value of subtyping ischemic stroke patients is for a better therapeutic decision-making process. The current classification methods are complex and time-consuming (hours to days). Specific blood-based biomarker measurements have promising potential to improve ischemic stroke mechanism classification. Over the past decades, the hypothesis that different blood-based biomarkers are associated with different ischemic stroke mechanisms is increasingly investigated. This review presents the recent studies that investigated blood-based biomarker characteristics differentiation between ischemic stroke mechanisms. Different blood-based biomarkers are specifically discussed (b-type natriuretic peptide, d-dimer, c-reactive protein, tumor necrosis factor-α, interleukin-6, interleukin-1β, neutrophil-lymphocyte ratio, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein and apolipoprotein A), as well as the different cut-off values that may be useful in specific classifications for cardioembolic and atherosclerosis etiologies. Lastly, the structure of a point-of-care biosensor device is presented, as a measuring tool on-site. The information presented in this review will hopefully contribute to the major efforts to improve the care for stroke patients. National Research Foundation (NRF) Published version This research was funded by the National Research Foundation (NRF) of Singapore under the Campus for Research Excellence and Technological Enterprise (CREATE) and the Singapore International Graduate Award (SINGA) for supporting D.H.

Bioluminescent bacteria whole-cell biosensors (WCBs) have been widely used in a range of sensing applications in environmental monitoring and medical diagnostics. However, most of them use planktonic bacteria cells that require complicated signal measurement processes and therefore limit the portability of the biosensor device. In this study, a simple and low-cost immobilization method was examined. The bioluminescent bioreporter bacteria was absorbed on a filter membrane disk. Further optimization of the immobilization process was conducted by comparing different surface materials (polyester and parafilm) or by adding glucose and ampicillin. The filter membrane disks with immobilized bacteria cells were stored at &minus, 20 &deg, C for three weeks without a compromise in the stability of its biosensing functionality for water toxicants monitoring. Also, the bacterial immobilized disks were integrated with smartphones-based signal detection. Then, they were exposed to water samples with ethanol, chloroform, and H2O2, as common toxicants. The sensitivity of the smartphone-based WCB for the detection of ethanol, chloroform, and H2O2 was 1% (v/v), 0.02% (v/v), and 0.0006% (v/v), respectively. To conclude, this bacterial immobilization approach demonstrated higher sensitivity, portability, and improved storability than the planktonic counterpart. The developed smartphone-based WCB establishes a model for future applications in the detection of environmental water toxicants.

A portable multi-channel surface plasmon resonance (SPR) biosensor device using prism-based wavelength interrogation is presented. LEDs were adopted as a simple and inexpensive light source, providing a stable spectrum bandwidth for the SPR system. The parallel light was obtained by a collimated unit and illuminated on the sensing chip at a specific angle. A simple, compact and cost-effective spectrometer part constituted of a series of lenses and a prism was designed for the collection of reflected light. Using the multi-channel microfluidic chip as the sensing component, spectral images of multiple tests could be acquired simultaneously, improving the signal processing and detection throughput. Different concentrations of sodium chloride aqueous solution were used to calibrate the device. The linear detection range was 4.32 × 10−2 refractive index units (RIU) and the limit of detection was 6.38 × 10−5 RIU. Finally, the performance of the miniaturized SPR system was evaluated by the detection of immunoglobulin G (IgG).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also known as 2019-nCov or nCovid-19) outbreak has become a huge public health issue due to its rapid transmission making it a global pandemic. Currently, there are no vaccines or drugs available for nCovid-19, hence early detection is crucial to help and manage the outbreak. Here, we report an in-house built biosensor device (eCovSens) and compare it with a commercial potentiostat machine for the detection of nCovid-19 spike protein antigen (nCovid-19 Ag) in spiked saliva samples. A potentiostat based sensor was fabricated using fluorine doped tin oxide electrode (FTO) drop casted with gold nanoparticle (AuNPs) and immobilized with nCovid-19 monoclonal antibody (nCovid-19 Ab) to measure change in the electrical conductivity. Similarly, eCovSens was used to measure change in electrical conductivity by immobilizing nCovid-19 Ab on screen printed carbon electrode (SPCE). The performances of both sensors were recorded upon interaction of nCovid-19 Ab with its specific nCovid-19 Ag. Under optimum conditions, the FTO based immunosensor and proposed SPCE-based biosensor device displayed high sensitivity for early detection of nCovid-19 Ag, ranging from 1 fM to 1 μM. Our in-house developed eCovSens device can successfully detect nCovid-19 Ag at 10 fM concentration in standard buffer that is in close agreement with FTO/AuNPs sensor where AuNPs were used for the amplification of the electrical signal. The limit of detection (LOD) was found to be 90 fM with eCovSens and 120 fM with potentiostst in case of spiked saliva samples. The proposed portable point of care (PoC) eCovSens device can be used as an alternative diagnostic tool for the rapid (within 10-30 s) detection of nCovid-19 Ag traces directly in patient saliva samples that displayed high sensitivity, stability, and specificity.

Laccase from Botryosphaeria rhodina MAMB-05 was covalently immobilized on carboxymethyl-botryosphaeran by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) in aqueous solution. This approach was employed to fabricate a novel laccase-based biosensor to electrochemically quantify quercetin (QCT), using a simple carbon black paste electrode as a transducer. The proposed biosensor was characterized by electrochemical impedance spectroscopy and Nyquist plots were used to evaluate the immobilization of the enzyme. For determining QCT, variables were optimized, that included experimental conditions for laccase immobilization, pH of the supporting electrolyte, and instrumental parameters of the electroanalytical technique. From square-wave-voltammograms, a linear dependence between the cathodic current peak and QCT concentration was observed within the range 4.98–50.0 × 10−8 mol L−1, with a theoretical detection limit of 2.6 × 10−8 mol L−1. The proposed method was successfully applied to determine QCT in beverages, pharmaceuticals, and biological samples. The proposed biosensor device presented good selectivity in the presence of uric acid, various inorganic ions, as well as other phenolic compounds, demonstrating the potential application of this biosensing platform in chemically complex solutions. Operational and analytical stability of the laccase-biosensor were evaluated, and good intra-day (SD = 1.23%) and inter-day (SD = 2.32%) repeatability, and long storage stability (SD = 3.47%) are presented.

Advancements that occurred during the last years in the diagnosis of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis infection, have prompted increased survival rates of patients. However, limitations related to the inefficiency of an early detection still remain; some techniques and laboratory methods do not have enough specificity and most instruments are expensive and require handling by trained staff. In order to contribute to a prompt and effective diagnosis of tuberculosis, we report the development of a portable, user-friendly, and low-cost biosensor device for its early detection. By using a label-free surface plasmon resonance (SPR) biosensor, we have established a direct immunoassay for the direct detection and quantification of the heat shock protein X (HspX) of Mtb, a well-established biomarker of this pathogen, directly in pretreated sputum samples. The method relies on highly specific monoclonal antibodies that are previously immobilized on the plasmonic sensor surface. This technology allows for the direct detection of the biomarker without amplification steps, showing a limit of detection (LOD) of 0.63 ng mL-1 and a limit of quantification (LOQ) of 2.12 ng mL-1. The direct analysis in pretreated sputum shows significant differences in the HspX concentration in patients with tuberculosis (with concentration levels in the order of 116-175 ng mL-1) compared with non-tuberculosis infected patients (values below the LOQ of the assay).

Nosocomial infections are a major concern at the worldwide level. Early and accurate identification of nosocomial pathogens is crucial to provide timely and adequate treatment. A prompt response also prevents the progression of the infection to life-threatening conditions, such as septicemia or generalized bloodstream infection. We have implemented two highly sensitive methodologies using an ultrasensitive photonic biosensor based on a bimodal waveguide interferometer (BiMW) for the fast detection of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), two of the most prevalent bacteria associated with nosocomial infections. For that, we have developed a biofunctionalization strategy based on the use of a PEGylated silane (silane-PEG-COOH) which provides a highly resistant and bacteria-repelling surface, which is crucial to specifically detect each bacterium. Two different biosensor assays have been set under standard buffer conditions: one based on a specific direct immunoassay employing polyclonal antibodies for the detection of P. aeruginosa and another one employing aptamers for the direct detection of MRSA. The biosensor immunoassay for P. aeruginosa is fast (it only takes 12 min) and specific and has experimentally detected concentrations down to 800 cfu mL-1 (cfu: colony forming unit). The second one relies on the use of an aptamer that specifically detects penicillin-binding protein 2a (PBP2a), a protein only expressed in the MRSA mutant, providing a photonic biosensor with the ability to identify the resistant pathogen MRSA and differentiate it from methicillin-susceptible S. aureus (MSSA). Direct, label-free, and selective detection of whole MRSA bacteria has been achieved, making possible the direct detection of also 800 cfu mL-1. According to the signal-to-noise (S/N) ratio of the device, a theoretical limit of detection (LOD) of around 49 and 29 cfu mL-1 was estimated for P. aeruginosa and MRSA, respectively. Both results obtained under standard conditions reveal the great potential this interferometric biosensor device has as a versatile and specific tool for bacterial detection and quantification, providing a rapid method for the identification of nosocomial pathogens within the clinical requirements of sensitivity for the diagnosis of infections.

© 2020 by the authors., Pneumocystis jirovecii is a fungus responsible for human Pneumocystis pneumonia, one of the most severe infections encountered in immunodepressed individuals. The diagnosis of Pneumocystis pneumonia continues to be challenging due to the absence of specific symptoms in infected patients. Moreover, the standard diagnostic method employed for its diagnosis involves mainly PCR-based techniques, which besides being highly specific and sensitive, require specialized personnel and equipment and are time-consuming. Our aim is to demonstrate an optical biosensor methodology based on surface plasmon resonance to perform such diagnostics in an efficient and decentralized scheme. The biosensor methodology employs poly-purine reverse-Hoogsteen hairpin probes for the detection of the mitochondrial large subunit ribosomal RNA (mtLSU rRNA) gene, related to P. jirovecii detection. The biosensor device performs a real-time and label-free identification of the mtLSU rRNA gene with excellent selectivity and reproducibility, achieving limits of detection of around 2.11 nM. A preliminary evaluation of clinical samples showed rapid, label-free and specific identification of P. jirovecii in human lung fluids such as bronchoalveolar lavages or nasopharyngeal aspirates. These results offer a door for the future deployment of a sensitive diagnostic tool for fast, direct and selective detection of Pneumocystis pneumonia disease., The ICN2 is funded by the CERCA program/Generalitat de Catalunya. The ICN2 was supported by the Severo Ochoa Centres of Excellence program funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706). The ICN2 and O.C.L. acknowledge the economic support of the Spanish MINECO, the Spanish Research Agency and the European Social Fund (ESF) for the grant for predoctoral contracts in the Subprograma Estatal de Formación del Programa Estatal de Promoción del Talento y su Empleabilidad (ref. BES-2017-080527) linked to the TEC 2016-78515-R project PREDICT. Dr C.S.H. is a recipient of an RMIT Vice Chancellor’s Postdoctoral Fellowship. This study was supported, in part, by the Red Iberoamericana sobre Pneumocystosis in the framework of The Ibero-American Programme for Science, Technology and Development (grant CYTED 212RT0450). Financial support was also provided by the Spanish Ministerio de Ciencia e Innovación (MICINN) (Projects CTQ2017-84415-R).

Celiac disease (CD) is a chronic autoimmune disorder induced in genetically susceptible individuals by the ingestion of gluten from wheat, rye, barley, or certain varieties of oats. A careful diet follow-up is necessary to avoid health complications associated with long-term gluten intake by the celiac patients. Small peptides (GIP, gluten immunogenic peptides) derived from gluten digestion, which are excreted in the urine and feces, have emerged as promising biomarkers to monitor gluten intake. We have implemented a simple and sensitive label-free point-of-care (POC) device based on surface plasmon resonance for the direct detection of these biomarkers in urine. The assay employs specific monoclonal antibodies and has been optimized for the detection of the 33-mer α2-gliadin, known as the main immunogenic peptide of wheat gluten, and for the detection of GIP. Direct detection in undiluted urine has been accomplished by using biosensing chips containing a robust and stable biorecognition layer, obtained after carefully optimizing the biofunctionalization protocol. Excellent limits of detection have been reached (1.6–4.0 ng mL−1 using mAb G12 and A1, respectively), which ensures the detection of gluten peptides even when the gluten intake is around the maximum tolerable amount in the digestive tract (, We received financial support from URINETEST Project (Retos Colaboración URINETEST RTC-2016-5452-1). ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706).

Made available in DSpace on 2020-12-12T01:00:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ZnO nanorods comprised of biosensors with Au nanoparticles are described in this study for detecting Hepatitis C virus (HCV). The biosensor device was constructed on a glass substrate with silver and gold electrodes. The ZnO nanorods were grown by microwave hydrothermal synthesis, and the Au nanoparticles were deposited by the sputtering method. The Au nanoparticles were deposited because of the right efficient of anti-HCV antibodies with cystamine and glutaraldehyde. The ZnO nanorods were evaluated using SEM images. The electrochemical biosensor shows a sensitive response to HCV with a detection limit of 0.25 μg/μL. The proposed sensor characteristics of high specificity, good reproducibility and remarkable stability will provide a sensitive, selective, and convenient approach for the detection of HCV. LIEC Institute of Chemistry São Paulo State University-UNESP School of Pharmaceutical Sciences São Paulo State University-UNESP LIEC Institute of Chemistry São Paulo State University-UNESP School of Pharmaceutical Sciences São Paulo State University-UNESP FAPESP: 2016/05269-6