New electrochemical method to deposit surface-enhanced Raman scattering-active silver nanoparticles on metal substrates

As shown in the literature, many methods have been developed to improve the signal, reproducibility and stability of surface-enhanced Raman scattering (SERS) for its reliable application. However, the fabrication needed is laborious. In this work, we propose an effective method to prepare SERS-active substrates with Ag nanoparticles (NPs) by a new electrochemical strategy of deposition-dissolution cycles (DDCs). This electrochemical method is based on a cathodic potential of 0.25 V and an anodic potential of 1.05 V vs. Ag/AgCl, which are applied in turn under sonication. The prepared SERS-active substrate demonstrates a large Raman scattering enhancement for adsorbed Rhodamine 6G (R6G). The practical detection limit for polypyrrole deposited on this substrate is 0.1 μC cm ^-2. Moreover, the prepared SERS-active substrates exhibit satisfactory reproducibility and thermal stability. The SERS spectrum of R6G on the newly developed substrate still performs well at a high temperature of 250°C.