SARS-Cov-2 receptor binding domain (RBD) detection using gold nanoparticle modified carbon electrode for electrochemical biosensor.

Coronavirus disease (COVID-19) confirmed cases spread worldwide and still rapidly increasing. Early detection and screening test is crucial to control the spread of the infection and prevent hospitals from collapse in handling COVID patients. Therefore, the development of point-of-care testing that allows rapid detection yet accuracy without utilizing laboratory is needed. Electrochemical biosensors can be a good solution by using SPCE due to allowing portable testing, simplicity, ease of operation, and the potential for mass production. Modification of the working electrode with nanomaterial is supposed to improve its analytical performance. AuNPs are potential materials to electrodeposited on the working electrode of SPCE to create a more significant electrode reaction, enhance the electron transfer, increase the conductivity, and act as anchoring materials due to their ability to strongly bind with thiolated protein. In this work, the scFv is immobilized on to gold nanoparticles-modified electrode as a bioreceptor to detect SARS-CoV-2 RBD. The use of scFv in this study will enhance antibody performance and reduce assay costs since it has the same or better specificity as the whole antibody in antigen binding. The electrochemical measurements show the successfully developed proof of concept of SARS-CoV-2 RBD biosensor with the change of current oxidation peak resulting from scFv and RBD incubation was 55.8% and 14.5%, respectively. [ABSTRACT FROM AUTHOR]