Fig. 1. Structure and detection principle of polymeric flat-plate waveguide-AuNPs SERS substrate

Fig. 2. Simulation of polymeric flat-plate waveguide-AuNPs SERS substrate structure.(a) 3D structure of substrate; (b) electric field distribution of incident surface; (c) electric field distribution around AuNPs surface

Fig. 3. Raman experimental results for different transmission lengths. (a) Raman spectrum of R6G, inset is a local magnification around wave number 1509 cm^-1; (b) intensity diagram at 1509 cm^-1, inset is a physical view of long-range detection

Fig. 4. Enhanced Raman spectra of different concentrations of R6G,inset is a partial magnification of 1×10^-8, 1×10^-7 mol/L R6G's Raman spectra

Fig. 5. Raman spectra of R6G tested ten times. (a) Raman spectra; (b) error bar

Fig. 6. Enhanced and normal Raman signals of R6G