Electrochemical Biosensor for the Detection of SARS-CoV-2 Main Protease and Its Inhibitor Ebselen

This work reported an electrochemical method for the detection of SARS-CoV-2 major protease (Mpro). Specifically, ferrocene (Fc)-labeled peptide substrates were immobilized on the gold nanoparticles (AuNPs)-modified electrode. Cleavage of the peptides by Mpro led to the release of Fc tags and the decrease of the electrochemical signals. The analytical performance of the biosensor for analysis of Mpro was investigated. Inhibiting the activity of Mpro prevented the cleavage of the peptide substrates. The method was successfully used to evaluate the inhibition efficiency of a well-known inhibitor.