Investigation of the mechanism of influence of colloidal gold/silver substrates in nonaqueous liquids on the surface enhanced Raman spectroscopy (SERS) of fullerenes C60 (C70)

Surface enhanced Raman scattering (SERS) spectra of C-60 (C-70) were obtained in nonaqueous colloidal systems with newly developed methods. The enhancement factor was estimated to be over 10(5). This paper aims at the investigation of a fine influence mechanism for SERS in the nonliquid phase, which may help bring forth the perfect SERS mechanism. The detailed investigation is based on abundant comparative experiments where we found that the SERS effect is sensitive not only to the character of colloidal particles, dielectric constants, and polarizability, but also to the substrates, the solvent intermediate, and even the coating techniques. These detailed comparisons enrich the proofs of the SERS mechanism and provide a new way to optimize SERS systems. (c) 2006 Elsevier Inc. All rights reserved.