Fig. 8.
(A) Synthesis of silica-QD nanobead probes for detection of SARS-CoV-2 and FluA at the same time, (B) conjugation of silica-QD nanobeads with SARS-CoV-2 NP and FluA, (C) application of developed beads to LFA-based biosensor and test working principle [142]; (D) Detail illustration of the SERS-LFA. (a) Positive result, the AuAg4−ATP@AgNPs-(gE-mAb) is captured at both the detector region (test and the control). (b) Negative result, the AuAg4−ATP@AgNPs-(gE-mAb) is captured at the control region. (c) Basic drawing and measurement of the positive reaction on the T line [153]; (E) Operating concept of the SERS-LFA biosensing platform. Y. pestis, F. tularensis, and B. anthracis LFA strips were dipped into wells of a 96-well ELISA plate containing mixes of SERS nanotags and varying quantities of bacteria in buffer solution. The generated immunocomplexes moved to the test line through capillary action, where their Raman signals were recorded and evaluated [157]. Reproduced with permission from ref. 142-153-157, Elsevier Ltd.