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

Abstract

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.

Functional Nanomaterials for Rapid Detection of SARS-CoV-2: a Review

“…电化学阻抗法 [35][36][37] 是通过对系统施加 5~10 mV 的小幅度正弦波交流电信号，测试工作电极上的生 物材料所表现出来的电阻和电容。在电化学阻抗谱 图中包括高频区的半圆部分和低频区的直线部分， 分别代表工作电极表面发生氧化还原反应时的电子 转移速率和电解质溶液中电荷扩散速率。电化学阻 抗传感器主要通过快速、灵敏的分析电极材料上电 阻变化，来反映待测目标分析物的浓度。目前，电 化学阻抗传感器已经在新冠病毒检测上有着独特的 运用 [35][36] 。…”