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Surface-Enhanced Raman Scattering-Active Au/SiO2 Nanocomposites Prepared Using Sonoelectrochemical Pulse Deposition Methods

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journal contribution
posted on 26.09.2012, 00:00 by Chun-Chao Chang, Kuang-Hsuan Yang, Yu-Chuan Liu, Ting-Chu Hsu, Fu-Der Mai
For improving signals, reproducibility, and stabilities of surface-enhanced Raman scattering (SERS), numerous technologies have recently been reported in the literature. However, the fabrication processes are usually complicated. It is well-known that nanoparticles (NPs) of Au and SiO2 are SERS active and inactive materials, respectively. In this work, a simple synthesis route based on sonoelectrochemical pulse deposition (SEPD) methods has been developed to synthesize effectively SERS-active Au/SiO2 nanocomposites (NCs) with an enhancement factor of 5.4 × 108. Experimental results indicate that pH value of solution and addition of SiO2 NPs before and after oxidation–reduction cycles (ORCs) can significantly influence the corresponding SERS activities. Encouragingly, the SERS of Rhodamine 6G (R6G) adsorbed on the developed Au/SiO2 NCs exhibits a higher intensity by more than 1 order of magnitude, as compared with that of R6G adsorbed on Au NPs synthesized using the same method. Moreover, this improved SERS activity is successfully verified from the mechanisms of electromagnetic (EM) and chemical (CHEM) enhancements.