Fig. 1. Characterization results of Ag nanoparticles. (a) Ultraviolet-visible spectrum, inset is FESEM image; (b) diameter distribution of Ag nanoparticles

Fig. 2. Influence of substrates on Raman signals. (a) Principle diagram of collecting Raman light; (b) light energy distribution with different reflectivity; (c) light energy density curves with different reflectivity; (d) relative reflectivity of different substrates; (e) peak values of different substrates at Raman displacement is 1360cm^-1; (f) normalized curves of simulation result and experimental result

Fig. 3. Preparation of SERS chip. (a) Microscopic images of Ag sol containing different proportions of ethylene glycol after drying; (b) picture of array detection area and silver sol droplets; (c) distribution of Ag nanoparticles in detection area

Fig. 4. SERS chip performance test results. (a) SERS of different concentrations of R6G solution; (b) SERS mapping of SERS chip; (c) bending SERS chip; (d) SERS mapping of chip after bending for many times