Improved performances on surface-enhanced Raman scattering based on electrochemically roughened gold substrates modified with SiO2 nanoparticles

In this work, we use electrochemical oxidation-reduction cycles (ORC) methods to prepare surface-enhanced Raman scattering (SERS)-active gold substrates modified with SiO2 nanoparticles to improve the corresponding SERS performances. Based on the modified substrates, the SERS of Rhodamine 6G (R6G) exhibits a higher intensity by 3-fold of magnitude, as compared with that of R6G adsorbed on a SERS-active Au substrate without the modification of SiO2 nanoparticles. Moreover, the SERS enhancement capabilities of the modified and the unmodified Au substrates are seriously destroyed at temperatures higher than 250 and 200 degrees C, respectively. These results indicate that the modification of SiO2 nanoparticles can improve the thermal stability of SERS-active substrates. The aging in SERS intensity is also depressed on this modified Au substrate due to the contribution of SiO2 nanoparticles to SERS effects. Copyright (C) 2009 John Wiley & Sons, Ltd.