BIOMIMETIC SENSORS FOR RAPID AND SENSITIVE SARS-CoV-2 DETECTION

Abstract: In the last two years, the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has impacted the entire world. SARS-CoV-2 detection methods include Polymerase Chain Reaction (PCR), which is expensive, and Rapid Antigen Test, which is not highly sensitive. Therefore, this study aimed for a viral diagnostic tool that is cost-effective and highly sensitive, a biomimetic biosensor.   The aim was to build a biomimetic biosensor using Surface Plasmon Resonance (SPR) based equipment. Three epitopes named here alpha 1, alpha 2, and alpha 3 from the angiotensin converting enzyme-2 (ACE-2), the target receptor for cell entry for SARS-CoV-2 and SARS-CoV in the body, were immobilized on a surface. Then, samples containing WT SARS-CoV-2 RBD, WT SARS-CoV-2 Spike, Delta SARS-CoV-2 RBD, and SARS-CoV RBD were injected over the surface. SPR allowed the detection of any binding that occurred.   The results revealed that the WT SARS-CoV-2 spike protein and the Delta SARS-CoV-2 RBD binding to alpha 2 showed the best results with high signals and high binding affinities. Alpha 1 interestingly showed good binding only two out of six times but the exact reason for that remains unknown. Alpha 3 did not seem to be promising as it either did not bind the analytes at all or was bound with very low signals.   These findings indicate that it is possible to build a biomimetic biosensor using peptides from ACE-2 to detect SARS-CoV-2, but further investigations are needed to optimize it. Future perspectives can include focusing on optimizing alpha 1 efficiency and finding the reason why it is not so stable.     Keywords: SARS-CoV-2, biosensor, SPR, ACE-2, spike, RBD