(417e) A Novel SERS-Based Assay for Detection of the Sars-Cov-2 Spike Protein

The COVID-19 pandemic has highlighted the need for the rapid development of sensitive diagnostic tests. We have developed a rapid, point-of-care assay to detect the spike protein of the SARS-CoV-2 virus. The assay relies on the use of scFv (single chain fragment variable) antibody fragments that bind the receptor binding domain of the SARS-CoV-2 spike protein, with immunocomplex detection using SERS (surface enhanced Raman spectroscopy). ScFv antibody fragments can be expressed in E. coli, making this approach less expensive than antibody production in animals or cell culture, while the sensitive SERS detection makes this assay more sensitive than lateral flow assays currently on the market. The assay has a limit of detection of 2x10³ SARS-CoV-2 genomes/ml or 5 fg/ml SARS-CoV-2 spike protein, which is below the viral load of an infectious individual. The assay recognizes the spike proteins of the alpha, beta, gamma, delta, and omicron variants of SARS-CoV-2, but does not recognize the closely related SARS-CoV, MERS-CoV, or common coronavirus strain HKU1 spike proteins. In this talk, I will discuss development and validation of the assay, as well as further development and improvement for our SERS-based SARS-CoV-2 detection.