SERS hotspots distribution of the highly ordered noble metal arrays on flexible substrates

Surface enhanced Raman scattering (SERS) is a surface-sensitive technique with high enhancement factor (EF), which has wide application in single molecule detection. In this paper, highly ordered noble metal NPs are fabricated on flexible substrates by nanoimprint lithography (NIL) and plasma sputtering technology for the SERS substrates. The preparation method was convenient and easy to control. The effect of size and gap between the metal NPs on the SERS hotspots distribution and activity has been discussed. The results show that the SERS achieves the. strongest for the coupling effect between the metal grains and wavelength matching of the extinction peak of metal with the Raman laser's excitation. The highly ordered noble metal SERS substrates exhibit high EF about 0.8 × 1011 and reproducibility of Raman signals with the RSD as low as 3.72%. Remarkably, these ordered Ag and Au SERS substrates are used to identify the wild LR from the false snowberries colored with purple potato pigment fast and nondestructively.