Improved Surface-Enhanced Raman Scattering Performances on Silver−Silica Nanocomposites

In this work, surface-enhanced Raman scattering (SERS)-active silver substrates were prepared by electrochemical methods via oxidation−reduction cycles. These SERS-active substrates were further modified with different contents of SiO 2 nanoparticles to improve their corresponding SERS performances. With the modified substrate prepared in a 0.1 mM SiO 2 solution, the SERS of Rhodamine 6G (R6G) exhibits a higher intensity by a 3-fold order of magnitude as compared with that of R6G adsorbed on a SERS-active Ag substrate without the incorporation of SiO 2 nanoparticles. Moreover, the modified substrate prepared in a 1 mM SiO 2 solution can improve the thermal stability of the SERS-active Ag substrate. The operation temperature of the modified Ag substrate can be raised by 50 °C. The aging SERS intensity is also depressed on this modified Ag substrate due to the contribution of SiO 2 nanoparticles to SERS effects.