scholarly journals An Effective SARS-CoV-2 Electrochemical Biosensor with Modifiable Dual Probes Using a Modified Screen-Printed Carbon Electrode

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1171
Author(s):  
Sow-Neng Pang ◽  
Yu-Lun Lin ◽  
Kai-Jie Yu ◽  
Yueh-Er Chiou ◽  
Wai-Hung Leung ◽  
...  

Due to the severe acute respiratory syndrome coronavirus (SARS-CoV-2, also called coronavirus disease 2019 (COVID-19)) pandemic starting in early 2020, all social activities ceased in order to combat its high transmission rate. Since vaccination combats one aspect for halting the spread of the virus, the biosensor community has looked at another aspect of reducing the burden of the COVID-19 pandemic on society by developing biosensors that incorporate point-of-care (POC) testing and the rapid identification of those affected in order to deploy appropriate measures. In this study, we aim first to propose a screen-printed carbon electrode (SPCE)-based electrochemical biosensor that meets the ASSURED criteria (i.e., affordable, sensitive, specific, user-friendly, rapid, equipment-free, and deliverable) for POC testing, but more importantly, we describe the novelty of our biosensor’s modifiability that uses custom dual probes made from target nucleic acid sequences. Additionally, regarding the sensitivity of the biosensor, the lowest sample concentration was 10 pM (p = 0.0257) without amplification, which might challenge the traditional technique of reverse transcriptase-polymerase chain reaction (RT-PCR). The purpose of this study is to develop a means of diagnostics for the current pandemic as well as to provide an established POC platform for future epidemics.

2020 ◽  
Vol 16 (5) ◽  
pp. 570-579
Author(s):  
Fuzi M. Fartas ◽  
Jaafar Abdullah ◽  
Nor A. Yusof ◽  
Yusran Sulaiman ◽  
Mohd I. Saiman ◽  
...  

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Results: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.


2021 ◽  
Vol 8 (2) ◽  
pp. 202040
Author(s):  
Yeni Wahyuni Hartati ◽  
Dina Ratna Komala ◽  
Diana Hendrati ◽  
Shabarni Gaffar ◽  
Ari Hardianto ◽  
...  

Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintaining the levels of sodium in blood plasma. A person with a family history of hypertension has a high enough amount of ENaC protein in the kidneys or other organs, so that the ENaC protein acts as a marker that a person is susceptible to hypertension. An aptasensor involves aptamers, which are oligonucleotides that function similar to antibodies, as sensing elements. An electrochemical aptasensor for the detection of ENaC was developed using a screen-printed carbon electrode (SPCE) which was modified by electrodeposition of cerium oxide (CeO 2 ). The aptamer immobilization was via the streptavidin–biotin system. The measurement of changes in current of the active redox [Fe(CN) 6 ] 3−/4− was carried out by differential pulse voltammetry. The surfaces of SPCE and SPCE/CeO 2 were characterized using scanning electron microscopy, voltammetry and electrochemical impedance spectroscopy. The Box–Behnken experimental optimization design revealed the streptavidin incubation time, aptamer incubation time and streptavidin concentrations were 30 min, 30 min and 10.8 µg ml −1 , respectively. Various concentrations of ENaC were used to obtain the linearity range of 0.05–3.0 ng ml −1 , and the limits of detection and quantification were 0.012 ng ml −1 and 0.038 ng ml −1 , respectively. This aptasensor method has the potential to measure the ENaC protein levels in urine samples as well as to be a point-of-care device.


2012 ◽  
Vol 571 ◽  
pp. 56-59
Author(s):  
Yu Fang Sha ◽  
Mei Zhao ◽  
Ming Quan Yang ◽  
Hai Xin Bai ◽  
Man Zhao

Biological multilayer films of redox polymer and horseradish peroxidase (HRP) were successfully assembled on a screen-printed carbon electrode using layer-by-layer (LBL) assembled method based on the electrostatic interaction. The screen-printed carbon electrode surface was modified by the positively charged redox polymer, and the negatively charged HRP by LBL method.


2021 ◽  
pp. 130574
Author(s):  
P.E. Resmi ◽  
Jeethu Raveendran ◽  
P.V. Suneesh ◽  
T. Ramanchandran ◽  
Bipin G Nair ◽  
...  

2014 ◽  
Vol 447 ◽  
pp. 162-168 ◽  
Author(s):  
Nicolaj Cruys-Bagger ◽  
Hirosuke Tatsumi ◽  
Kim Borch ◽  
Peter Westh

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