An integrated fluorescent lateral flow assay for multiplex point-of-care detection of four respiratory viruses

This work established a highly sensitive and specific quantum dot nanobeads-based lateral flow assay for multiplex detection of four respiratory virus markers at point of care. The respiratory virus antigens were detected by fluorescent lateral flow strips within 20 min. The limits of detection for SARS-CoV-2 antigen, IAV antigen, IBV antigen, and ADV antigen were 0.01 ng/mL, 0.05 ng/mL, 0.31 ng/mL, and 0.40 ng/mL, respectively, which were superior to that of conventional AuNPs-based colorimetric lateral flow assay. The coefficients of variation of the test strip were 6.09%, 2.24%, 7.92%, and 12.43% for these four antigens, which indicated that the proposed method had good repeatability. The specificity of the detection system was verified by different combinations of these four respiratory viruses and several other respiratory pathogens. These results indicated that this method could simultaneously detect SARS-CoV-2, IAV, IBV and ADV in a short assay time, showing the remarkable potential for the rapid and multiplex detection of respiratory viruses in resource-limited settings.