The limit of detection(LOD) of this peptide-coated nanofibril sensor can be as low as 2–10ng/mL for the S-protein in a saliva sample, and the biosensor wouldallow rapid and cost-effective in-home COVID-19 self-diagnosis withoutadditional equipment, labor, and sample processing, thus enablingthis inexpensive COVID-19 diagnostic to be able to reach a broaderrange of the population. This evidence concerns the gene PROS1 and COVID-19.