Fig. 7.

Sensitivity enhancement based on SERS. A Schematic illustration of the core–shell SERS nanotag–based multiplex LFA for three cardiac biomarkers detection [121]. B Schematic illustration of quantitative LFA for three cardiac biomarkers detection on a single T line with different roman dyes encoded core–shell SERS nanotags [124]. C Schematic illustration of the principle of SERS paper-based lateral flow strip (PLFS) based on HGN [125]. (a) Top and side views; (b) side view before and after detection of protein biomarker; (c) optical results of PLFS assembled in cassettes in the presence (upper) and absence (bottom) of the target protein