An immunosensor based on a high performance dual-gate oxide semiconductor thin-film transistor for rapid detection of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of an infectious disease that has led the WHO to declare its highest level (6) pandemic. The coronavirus disease 2019 (COVID-19) has spread rapidly around the world, and the number of confirmed cases has passed 246 million as of November 2021. Therefore, precise and fast virus detection protocols need to be developed to cope with the rapid spread of the virus. Here, we present a high performance dual-gate oxide semiconductor thin-film transistor (TFT)-based immunosensor for detecting SARS-CoV-2. The immunosensor has an indium tin oxide sensing membrane to which the antibody against the SARS-CoV-2 spike S1 protein can be immobilized through functionalization. The dual-gate TFT was stable under ambient conditions with near-zero hysteresis; capacitive coupling yields a 10.14 ± 0.14-fold amplification of the surface charge potential on the sensing membrane and improves the pH sensitivity to 770.1 ± 37.74 mV pH-1 above the Nernst limit. The immunosensor could rapidly detect the SARS-CoV-2 spike S1 protein and cultured SARS-CoV-2 in 0.01× PBS with high antigen selectivity and sensitivity. Our immunosensor can accurately measure the electrical changes originated from SARS-CoV-2, without the need for polymerase chain reaction tests or labeling.

Penta-peptide ATN-161 based neutralization mechanism of SARS-CoV-2 spike protein.

SARS-CoV-2 has become a big challenge for the scientific community worldwide. SARS-CoV-2 enters into the host cell by the spike protein binding with an ACE2 receptor present on the host cell. Developing safe and effective inhibitor appears an urgent need to interrupt the binding of SARS-CoV-2 spike protein with ACE2 receptor in order to reduce the SARS-CoV-2 infection. We have examined the penta-peptide ATN-161 as potential inhibitor of ACE2 and SARS-CoV-2 spike protein binding, where ATN-161 has been commercially approved for the safety and possess high affinity and specificity towards the receptor binding domain (RBD) of S1 subunit in SARS-CoV-2 spike protein. We carried out experiments and confirmed these phenomena that the virus bindings were indeed minimized. ATN-161 peptide can be used as an inhibitor of protein-protein interaction (PPI) stands as a crucial interaction in biological systems. The molecular docking finding suggests that the binding energy of the ACE2-spike protein complex is reduced in the presence of ATN-161. Protein-protein docking binding energy (-40.50 kcal/mol) of the spike glycoprotein toward the human ACE2 and binding of ATN-161 at their binding interface reduced the biding energy (-26.25 kcal/mol). The finding of this study suggests that ATN-161 peptide can mask the RBD of the spike protein and be considered as a neutralizing candidate by binding with the ACE2 receptor. Peptide-based masking of spike S1 protein (RBD) and its neutralization is a highly promising strategy to prevent virus penetration into the host cell. Thus masking of the RBD leads to the loss of receptor recognition property which can reduce the chance of infection host cells.