On-site severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) serological assays allow for timely in-field decisions to be made regarding patient status, also enabling population-wide screening to assist in controlling the coronavirus disease 2019 (COVID-19) pandemic. Here we propose a rapid microfluidic serological assay with two unique functions of nanointerstice filling and digitized flow control, which enable the fast/robust filling of the sample fluid as well as precise regulation of duration and volume of immune reaction. Developed microfluidic assay showed enhanced limit of detection, and 91.67% sensitivity and 100% specificity (n = 152) for clinical samples of SARS CoV-2 patients. The assay enables daily monitoring of IgM/IgG titers and patterns, which could be crucial parameters for convalescence from COVID-19 and provide important insight into how the immune system responds to SARS CoV-2. The developed on-site microfluidic assay presented the mean time for IgM and IgG seroconversions, indicating that these titers plateaued days after seroconversion. The mean duration from day 0 to PCR negativity was 19.4 days (median 20 d, IQR 16–21 d), with higher IgM/IgG titres being observed when PCR positive turns into negative. Simple monitoring of these titres promotes rapid on-site detection and comprehensive understanding of the immune response of COVID-19 patients.
Bibliographical noteFunding Information:
H.K, Y.S, and S.C were supported by Samsung Research Funding and the Incubation Center of Samsung Electronics under Project SRFC-MA1502-51; P.K.B, S.Y.Y, J.K, and Y.B.S were supported by the BioNano Health-Guard Research Center funded by the Ministry of Science and ICT (MSIT) of South Korea as a Global Frontier Project (Grant number H-GUARD_2013M3A6B2078950 ).
© 2021 Elsevier B.V.
ASJC Scopus subject areas
- Biomedical Engineering