An Ultrasensitive Biosensor for Quantifying the Interaction of SARS-CoV-2 and Its Receptor ACE2 in Cells andin vitro

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is currently spreading and mutating with increasing speed worldwide. Therefore, there is an urgent need for a simple, sensitive, and high-throughput (HTP) assay to quantify virus-host interaction in order to quickly evaluate infectious ability of mutant virus and develop or validate virus-inhibiting drugs. Here we have developed an ultrasensitive bioluminescent biosensor to evaluate virus-cell interaction by quantifying the interaction between SARS-CoV-2 receptor binding domain (RBD) and its cellular receptor angiotensin-converting enzyme 2 (ACE2) both in living cells andin vitro. We have successfully used this novel biosensor to analyze SARS-CoV-2 RBD mutants, and evaluated candidate small molecules (SMs), antibodies, and peptides that may block RBD:ACE2 interaction. This simple, rapid and HTP biosensor tool will significantly expedite detection of viral mutants and anti-COVID-19 drug discovery processes.