High-Accuracy Multiplexed SARS-CoV-2 Antibody Assay with Avidity and Saliva Capability on a Nano-Plasmonic Platform

Liu, T.; Hsiung, J.; Zhao, S.; Kost, J.; Sreedhar, D.; Olson, K.; Keare, D.; Roche, J.; Hanson, C. V.; Press, C.; Boggs, J.; Rodriguez-Soto, J. P.; Montoya, J. G.; Tang, M.; Dai, H.

doi:10.1101/2020.06.16.155580

bioRxiv · 10.1101/2020.06.16.155580

High-Accuracy Multiplexed SARS-CoV-2 Antibody Assay with Avidity and Saliva Capability on a Nano-Plasmonic Platform

Liu, T.·Hsiung, J.·Zhao, S.·Kost, J.·Sreedhar, D.·Olson, K.·Keare, D.·Roche, J.·Hanson, C. V.·Press, C.·Boggs, J.·Rodriguez-Soto, J. P.·Montoya, J. G.·Tang, M.·Dai, H.

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Abstract

The outbreak and rapid spread of SARS-CoV-2 virus has led to a dire global pandemic with millions of people infected and ~ 400,000 deaths thus far. Highly accurate detection of antibodies for COVID-19 is an indispensable part of the effort to combat the pandemic1,2. Here we developed two-plex antibody detection against SARS-CoV-2 spike proteins3 (the S1 subunit and receptor binding domain RBD) in human serum and saliva on a near-infrared nano-plasmonic gold (pGOLD) platform4-8. By testing nearly 600 serum samples, pGOLD COVID-19 assay achieved ~ 99.78 % specificity for detecting both IgG and IgM with 100 % sensitivity in sera collected > 14 days post disease symptom onset, with zero cross-reactivity to other diseases. Two-plex correlation analysis revealed higher binding of serum IgM to RBD than to S1. IgG antibody avidity toward multiple antigens were measured, shedding light on antibody maturation in COVID-19 patients and affording a powerful tool for differentiating recent from remote infections and identifying re-infection by SARS-CoV-2. Just as important, due to high analytical sensitivity, the pGOLD COVID-19 assay detected minute amounts of antibodies in human saliva, offering the first non-invasive detection of SARS-CoV-2 antibodies.

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Liu, T., Hsiung, J., Zhao, S., Kost, J., Sreedhar, D., Olson, K., Keare, D., Roche, J., Hanson, C. V., Press, C., Boggs, J., Rodriguez-Soto, J. P., Montoya, J. G., Tang, M., Dai, H.. 2020-06-17. High-Accuracy Multiplexed SARS-CoV-2 Antibody Assay with Avidity and Saliva Capability on a Nano-Plasmonic Platform. https://doi.org/10.1101/2020.06.16.155580

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