Impedimetric Sensing: An Emerging Tool for Combating the COVID-19 Pandemic.

The COVID-19 pandemic revealed a pressing need for the development of sensitive and low-cost point-of-care sensors for disease diagnosis. The current standard of care for COVID-19 is quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). This method is sensitive, but takes time, effort, and requires specialized equipment and reagents to be performed correctly. This make it unsuitable for widespread, rapid testing and causes poor individual and policy decision-making. Rapid antigen tests (RATs) are a widely used alternative that provide results quickly but have low sensitivity and are prone to false negatives, particularly in cases with lower viral burden. Electrochemical sensors have shown much promise in filling this technology gap, and impedance spectroscopy specifically has exciting potential in rapid screening of COVID-19. Due to the data-rich nature of impedance measurements performed at different frequencies, this method lends itself to machine-leaning (ML) algorithms for further data processing. This review summarizes the current state of impedance spectroscopy-based point-of-care sensors for the detection of the SARS-CoV-2 virus. This article also suggests future directions to address the technology's current limitations to move forward in this current pandemic and prepare for future outbreaks.

Rapid SARS-CoV-2 testing with duplexed recombinase polymerase amplification and a bacteriophage internal control

Without global mass vaccination, COVID-19 will continue to infect and cause serious illness, disproportionately in low- and middle-income countries. Point-of-care and home-based nucleic acid amplification tests (NAATs) are valuable tools to control COVID-19 transmission. Here we present a rapid isothermal NAAT for duplexed detection of SARS-CoV-2 and an MS2 bacteriophage internal control. This assay amplifies RNA in less than 15 minutes, utilizes a low temperature of 39°C, and has fluorescence or visual lateral flow readout. This positions our assay for use in low-cost paper-based nucleic acid diagnostic devices for ultrasensitive and reliable COVID-19 detection in POC or home-based settings. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.