Archive | 2021
AuNP Coupled Rapid Flow-Through Dot-Blot Immuno-Assay for COVID-19 (SARS-CoV-2) Explicit IgG Antibody Revelation
Abstract
56 Background: Flow-through dot-blot assay (FT-DBA) for SARS-CoV-2 specific IgG 57 detection will provide a reliable and affordable immunoassay for the rapid 58 serosurveillance against COVID-19. 59 Method: SARS-CoV-2 antigens were immobilized on nitrocellulose membrane to 60 capture IgG immunoglobulins, which were then detected with AuNP anti-human IgG. A 61 total of 181 samples were characterized with in-house and commercial immunoassay. 62 The positive panel consisted of RT-PCR positive samples from patients with both <14 63 days and >14 days from the onset of symptoms, while the negative panel contained 64 samples collected either from the pre-pandemic era dengue patients from healthy 65 donors during the pandemic period. 66 Results: In-house ELISA selected a total of 79 true seropositive and 100 seronegative 67 samples. The sensitivity of samples with <14 days using FT-DBA was 94.7% which 68 increased to 100% for samples >14 days. The overall detection sensitivity and specificity 69 were 98.8% and 98%, respectively, whereas the overall PPV and NPV were 97.6% and 70 99%. Moreover, comparative analysis between ELISA and FT-DBA revealed clinical 71 agreement of Cohen’s Kappa value of 0.944. 72 Conclusion: The assay can confirm past SARS-CoV-2 infection with high accuracy within 73 2 minutes compared to ELISA. It can help track SARS-CoV-2 disease progression, 74 population screening, and vaccination response. 75