Strategy to improve stability of surface-enhanced raman scattering-active Ag substrates

Surface-enhanced Raman scattering (SERS)-active Ag substrates were popularly employed for evaluating the structural situation of analytes because SERS-active Ag substrates can demonstrate more significant SERS effects than Au and Cu substrates. However, the stability of SERS-active Ag substrates is an issue of concern in their application. In this work, SERS-active modified Ag substrates were simply prepared in 0.1 N HCl solutions containing Al ₂O₃ nanoparticles by electrochemical methods. Experimental results indicate that the Al₂O₃-modified Ag substrate can significantly improve its thermal stability by raising the operation temperature of the Ag substrate by over 100 °C. Moreover, the aging of SERS enhancement capabilities in an atmosphere of 50% relative humidity (RH) and 20% (v/v) O₂ at 30 °C is markedly depressed based on this Al ₂O₃-modified Ag substrate.