Linear spot Raman detector for the bi-channel immunochromatographic assay to simultaneously detect respiratory viruses

The rapid and accurate measurement of Raman signals on the test line (T-line) of surface-enhanced Raman scattering immunochromatography assay (SERS-ICA) strip is necessary for on-site detection based on SERS. Here, a novel linear spot Raman detector which can directly collect the SERS signals of the whole T-line on the dual-diagnostic SERS-ICA strip is developed for detection of multiple respiratory viruses via two magnetic SERS tags within 26 min. The tags modified with two Raman reporter molecules can specifically recognize two viruses, thus enabling the simultaneous detection of both viruses on one T-line. Measured by the linear Raman detector, the limits of detection of the proposed dual-diagnostic SERS-ICA strip is as low as 870 and 263 copies/mL for severe acute respiratory syndrome coronavirus 2 and H1N1, respectively. The dual-diagnostic strip combined with the novel Raman detector herein are of great importance in the differential diagnosis of respiratory pathogens and show potential in the rapid and accurate diagnosis and control of emerging acute respiratory diseases.