scholarly journals A SARS-CoV-2 aptasensor based on electrochemical impedance spectroscopy and low-cost gold electrode substrates.

2021 ◽  
Author(s):  
Perrine Lasserre ◽  
Banushan Balansethupathy ◽  
Vincent J. Vezza ◽  
Adrian Butterworth ◽  
Alexander MacDonald ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Low Cost ◽  
Glucose Monitoring ◽  
High Sensitivity ◽  
Blood Glucose Monitoring ◽  
Label Free ◽  
Rna Sequences ◽  
Point Of Use ◽  
Lateral Flow Assays ◽  
Impedimetric Biosensor

SARS-CoV-2 diagnostic practices broadly involve either qPCR based nucleic amplification or lateral flow assays (LFAs). qPCR based techniques suffer from the disadvantage of requiring thermal cycling (difficult to implement for low-cost field use) leading to limitation on sample to answer time, the potential to amplify viral RNA sequences after a person is no longer infectious and being reagent intense. LFA performance is restricted by qualitative or semi-quantitative readouts, limits on sensitivity and poor reproducibility. Electrochemical biosensors, and particularly glucose test strips, present an appealing platform for development of biosensing solutions for SARS-CoV-2 as they can be multiplexed and implemented at very low cost at point of use with high sensitivity and quantitative digital readout. This work reports the successful raising of an Opti-mer sequence for the spike protein of SARS-CoV-2 and then development of an impedimetric biosensor which utilises thin film gold sensors on low-cost laminate substrates from home blood glucose monitoring. Clinically relevant detection levels for SARS-CoV-2 are achieved in a simple, label-free measurement format using sample incubation times of 15 minutes. The biosensor developed here is compatible with mass manufacture, is sensitive and low-cost CE marked readout instruments already exist. These findings pave the way to a low cost and mass manufacturable test with the potential to overcome the limitations associated with current technologies.

scholarly journals Integrating high-performing electrochemical transducers in lateral flow assay

2021 ◽  
Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Analytical Performance ◽  
Label Free ◽  
High Performing ◽  
Lateral Flow Assays ◽  
Electrochemical Transducers

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

scholarly journals Diazonium-Modified Screen-Printed Electrodes for Immunosensing Growth Hormone in Blood Samples

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 88 ◽  
Author(s):  
Nan Li ◽  
Ari M. Chow ◽  
Hashwin V. S. Ganesh ◽  
Melanie Ratnam ◽  
Ian R. Brown ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
High Sensitivity ◽  
Sample Volume ◽  
Screening Methods ◽  
Serum Samples ◽  
Potential Applicability ◽  
Screen Printed

Altered growth hormone (GH) levels represent a major global health challenge that would benefit from advances in screening methods that are rapid and low cost. Here, we present a miniaturized immunosensor using disposable screen-printed carbon electrodes (SPCEs) for the detection of GH with high sensitivity. The diazonium-based linker layer was electrochemically deposited onto SPCE surfaces, and subsequently activated using covalent agents to immobilize monoclonal anti-GH antibodies as the sensing layer. The surface modifications were monitored using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The dissociation constant, Kd, of the anti-GH antibodies was also determined as 1.44 (±0.15) using surface plasmon resonance (SPR). The immunosensor was able to detect GH in the picomolar range using a 20 µL sample volume in connection with electrochemical impedance spectroscopy (EIS). The selectivity of the SPCE-based immunosensors was also challenged with whole blood and serum samples collected at various development stages of rats, demonstrating the potential applicability for detection in biological samples. Our results demonstrated that SPCEs provided the development of low-cost and single-use electrochemical immunosensors in comparison with glassy carbon electrode (GCE)-based ones.

A multipurpose biochip for food pathogen detection

2016 ◽  
Vol 8 (15) ◽  
pp. 3055-3060 ◽  
Author(s):  
Elisabetta Primiceri ◽  
Maria Serena Chiriacò ◽  
Francesco de Feo ◽  
Elisa Santovito ◽  
Vincenzina Fusco ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Low Cost ◽  
High Sensitivity ◽  
Label Free ◽  
Food Pathogen

We realized an innovative biosensing platform with high sensitivity, low-cost and label-free features forS. aureusandL. monocytogenesdetection from meat.

scholarly journals Fabrication of AuNPs/MWCNTS/Chitosan Nanocomposite for the Electrochemical Aptasensing of Cadmium in Water

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 105
Author(s):  
Selma Rabai ◽  
Ahlem Teniou ◽  
Gaëlle Catanante ◽  
Messaoud Benounis ◽  
Jean-Louis Marty ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Electrochemical Biosensor ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Applied Potential ◽  
Toxic Heavy Metals ◽  
Cadmium Detection ◽  
Interfering Ions

Cadmium (Cd2+) is one of the most toxic heavy metals causing serious health problems; thus, designing accurate analytical methods for monitoring such pollutants is highly urgent. Herein, we report a label-free electrochemical aptasensor for cadmium detection in water. For this, a nanocomposite combining the advantages of gold nanoparticles (AuNPs), carbon nanotubes (CNTs) and chitosan (Cs) was constructed and used as immobilization support for the cadmium aptamer. First, the surface of a glassy carbon electrode (GCE) was modified with CNTs-CS. Then, AuNPs were deposited on CNTs-CS/GCE using chrono-amperometry. Finally, the immobilization of the amino-modified Cd-aptamer was achieved via glutaraldehyde cross-linking. The different synthesis steps of the AuNPs/CNTs/CS nano assembly were characterized by cyclic voltammetry (CV). Electrochemical impedance spectroscopy (EIS) was employed for cadmium determination. The proposed biosensor exhibited excellent performances for cadmium detection at a low applied potential (−0.5 V) with a high sensitivity (1.2 KΩ·M−1), a detection limit of 0.02 pM and a wide linear range (10−13–10−4 M). Moreover, the aptasensor showed a good selectivity against the interfering ions: Pb2+; Hg2+ and Zn2+. Our electrochemical biosensor provides a simple and sensitive approach for Cd2+ detection in aqueous solutions, with promising applications in the monitoring of trace amounts of heavy metals in real samples.

scholarly journals A GPCR-based yeast biosensor for biomedical, biotechnological, and point-of-use cannabinoid determination

2022 ◽  
Author(s):  
Karel Miettinen ◽  
Nattawat Leelahakorn ◽  
Aldo Almeida ◽  
Yong Zhao ◽  
Lukas Hansen ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Low Cost ◽  
Real Life ◽  
High Sensitivity ◽  
Structural Diversity ◽  
High Throughput Analysis ◽  
Synthetic Drugs ◽  
Point Of Use ◽  
Whole Cell Biosensor ◽  
G Protein Coupled

Abstract The decriminalization of cannabis and the growing interest in cannabinoids as therapeutics require efficient methods to discover novel compounds and monitor cannabinoid levels in human samples and products. However, current methods are limited by the structural diversity of the active compounds. Here, we construct a G-protein coupled receptor-based yeast whole-cell biosensor, optimize it to achieve high sensitivity and dynamic range, and prove its effectiveness in three real-life applications. First, we screen a library of compounds to discover two novel agonists and four antagonists and demonstrate that our biosensor can democratize GPCR drug discovery by enabling low-cost high-throughput analysis using open-source automation. Subsequently, we bioprospect 54 plants to discover a novel phytocannabinoid, dugesialactone. Finally, we develop a robust portable device, analyze body-fluid samples, and confidently detect illicit synthetic drugs like “Spice”/“K2”. Taking advantage of the extensive sensing repertoire of GPCRs, this technology can be extended to detect numerous other compounds.

scholarly journals Colorimetric Sensing with Gold Nanoparticles on Electrowetting-Based Digital Microfluidics

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1423
Author(s):  
Zhen Gu ◽  
Jing-Jing Luo ◽  
Le-Wei Ding ◽  
Bing-Yong Yan ◽  
Jia-Le Zhou ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Low Cost ◽  
Digital Microfluidics ◽  
High Sensitivity ◽  
Bulk Solution ◽  
Label Free ◽  
Colorimetric Sensing ◽  
Wide Range ◽  
The Stability ◽  
Digital Microfluidic

Digital microfluidic (DMF) has been a unique tool for manipulating micro-droplets with high flexibility and accuracy. To extend the application of DMF for automatic and in-site detection, it is promising to introduce colorimetric sensing based on gold nanoparticles (AuNPs), which have advantages including high sensitivity, label-free, biocompatibility, and easy surface modification. However, there is still a lack of studies for investigating the movement and stability of AuNPs for in-site detection on the electrowetting-based digital microfluidics. Herein, to demonstrate the ability of DMF for colorimetric sensing with AuNPs, we investigated the electrowetting property of the AuNPs droplets on the hydrophobic interface of the DMF chip and examined the stability of the AuNPs on DMF as well as the influence of evaporation to the colorimetric sensing. As a result, we found that the electrowetting of AuNPs fits to a modified Young–Lippmann equation, which suggests that a higher voltage is required to actuate AuNPs droplets compared with actuating water droplets. Moreover, the stability of AuNPs was maintained during the processing of electrowetting. We also proved that the evaporation of droplets has a limited influence on the detections that last several minutes. Finally, a model experiment for the detection of Hg2+ was carried out with similar results to the detections in bulk solution. The proposed method can be further extended to a wide range of AuNPs-based detection for label-free, automatic, and low-cost detection of small molecules, biomarkers, and metal ions.

Design and Validation of a Low-Cost Non-Invasive Device to Detect Overnight Hypoglycemia

2018 ◽  
Author(s):  
Jonathan Lesko ◽  
Stephen Seibert ◽  
Yong Zhu
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Electrodermal Activity ◽  
Low Cost ◽  
Glucose Monitoring ◽  
Blood Glucose Monitoring ◽  
Life Threatening ◽  
Invasive Device ◽  
The Individual

Research in the field of blood glucose monitoring systems has led to incredible advancements over the past several decades. The blood glucose level of a diabetic patient is vital to monitor since large swings in blood sugar can cause life threatening damage to the individual. The importance of blood glucose monitoring increases when a patient experiences hypoglycemia, which can be very dangerous. The objective of this project is to create a low cost portable device that utilizes the modular bio-signal sensor kit BITalino and Arduino Uno microcontroller to measure and process the electrodermal activity (EDA) and electrocardiography (ECG) signals that can be associated with a drop in the subject’s blood glucose level to detect hypoglycemia in diabetics.

A low-cost mobile platform for whole blood glucose monitoring using colorimetric method

2021 ◽  
Vol 162 ◽  
pp. 105814
Author(s):  
Han Zhang ◽  
Zheyuan Chen ◽  
Jing Dai ◽  
Wei Zhang ◽  
Yuqian Jiang ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Whole Blood ◽  
Low Cost ◽  
Colorimetric Method ◽  
Glucose Monitoring ◽  
Mobile Platform ◽  
Blood Glucose Monitoring

scholarly journals Solvothermal synthesis of Fe3O4 nanospheres for high-performance electrochemical non-enzymatic glucose sensor

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiasheng Xu ◽  
Yuting Sun ◽  
Jie Zhang
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Glucose Sensor ◽  
Limit Of Detection ◽  
Glucose Monitoring ◽  
High Sensitivity ◽  
Blood Glucose Monitoring ◽  
Glucose Detection ◽  
Uniform Size ◽  
Long Term Stability

Abstract Ferroferric oxide (Fe3O4) nanospheres have been synthesized via a facile solvothermal procedure to serve as an electrode material for high performance non-enzymatic glucose sensor. The as-synthesized Fe3O4 nanospheres with a uniform size from 16 to 18 nm, which can increase the reaction contact area and the active sites in the process of glucose detection. Benefiting from the particular nanoscale structure, the Fe3O4 nanospheres obviously enhanced the activity of electrocatalytic oxidation towards glucose. When the Fe3O4 nanospheres material was used for non-enzymatic glucose sensor, several electrochemical properties including the high sensitivity 6560 μA mM−1 cm−2 (0.1–1.1 mM), limit of detection 33 μM (S/N = 3) and good long-term stability were well demonstrated. Furthermore, Fe3O4 nanospheres electrode confirmed the excellent performance of selectivity in glucose detection with the interfering substances existed such as urea, citric acid, ascorbic acid, and NaCl. Due to the excellent electrocatalytic activity in alkaline solution, the Fe3O4 nanospheres material can be considered as a promising candidate in blood glucose monitoring.

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