A fabrication of the surface-enhanced Raman scattering (SERS) active substrates has been developed by immersion plating of the silver onto porous silicon (Ag-por-Si). Effects of the porous silicon morphology on the structure of the Ag films have been analyzed by scanning electronic microscope. Activity of the Ag-coated por-Si toward SERS was estimated using water-soluble porphyrins as analyte molecules. The Ag-por-Si samples were appeared to be sensitive and stable SERS-active substrates. It has been found that the variation of SERS signal scanned over the sample surface is less than 9%. Additionally, plates of Ag-por-Si displayed high sensitivity being stored within 1 month in the air. It was shown that even several minutes incubation of Ag-por-Si in solution is enough to obtain well-defined SERS signal. SERS spectra of the water-soluble cationic tetrakis(N-methylpyridyl)porphyrin (H₂TMPyP4) and anionic tetrakis(sulfonatophenyl)porphyrin (H₂TPPS) were compared with their resonance Raman (RR) spectra. For the cationic H₂TMPyP4 the partial metallation has been detected during impregnation of the porphyrin molecules on the Ag-por-Si surface. In case of the anionic H₂TPPS there was no evidence of the silver complex formation.

Date Published: 31 July 2007
PDF: 6 pages
Proc. SPIE 6728, ICONO 2007: Novel Photonics Materials; Optics and Optical Diagnostics of Nanostructures, 672828 (31 July 2007); doi: 10.1117/12.752423

Published in SPIE Proceedings Vol. 6728:
ICONO 2007: Novel Photonics Materials; Optics and Optical Diagnostics of Nanostructures
Oleg Andreevich Aktsipetrov; Sergey V. Gaponenko; Nikolay I. Zheludev; Vladimir M. Shalaev, Editor(s)