An uncomplicated electrochemical sensor combining a perfluorocarbon SAM and ACE2 as the bio-recognition element to sensitively and specifically detect SARS-CoV-2 in complex samples.

Emerging in late 2019, the SARS-CoV-2 virus has had a devastating health and economic effects around the world forcing governments to enact restrictions on day to day life, resulting in severe economic and social disruption. The virus has stimulated new research in the fields of drug development, vaccinology and diagnostic testing. Here we present the basis for a simple, mass manufacturable saliva based electrochemical assay for the SARS-CoV-2 virus acheived through adsorption of the Angiotsnsin Converting Enzyme 2 (ACE2) into thiolated amphiphobic prefluoro monolayer assemled on a gold sensor surface. Following sensor preparation, it is possible to measure specific binding of recombinant spike protein and discriminate positive and negative samples of inactivated SARS-CoV-2 following 30 minutes incubation under ambient conditions. Representative calculations of limits of detection are made for recombinant spike protein (1.68 ng/ml) and inactivated virus (37.8 dC/mL). The assay as presented ultimately shows discrimination between positive and negative inactivated SARS-CoV-2 samples originating from clinical molecular standards kit intended for clinical and biomedical assay validation, and which is designed to mimic clinical samples through presence of cells and proteins in the sample medium. The simple design of the label free measurement and the selection of reagents involved means the assay has clear potential for transfer onto mass producible units such as screen-printed electrodes similar to glucose-format test strips, to enable widespread, low cost and rapid testing for SARS-CoV-2 in the general population