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This paper presents the surface-enhanced hyper-Raman scattering (SEHRS) effect of basic fuchsin (BF) adsorbed on the silver colloid. On the basis of the absorption spectra, a new absorption band at 1000 nm has been observed in the case of BF adsorption on the silver colloid. The result indicates that surface electromagnetic enhancement also appears at the incident photon frequency in the near-IR region, which plays an important role in the SEHRS signals. The electromagnetic enhancement factor (2.0×104) is estimated by using electromagnetic model. Additionally, surface-enhanced second-harmonic generation (SHG) effect in the cases of pure silver colloid, silver colloid plus adsorbed molecule and KCl solution has been detected.

The energy transfer effect between molecules adsorbed on rounghened silver surface has been investigated both theoretically and experimentally. The theoretical results indicate that when the emission frequency of the donor and the adsorption frequency of

The band of charge transfer transition was detected in optical absorbance spectra whenmolecule adsorbed on the silver surface in silver sol and silver mirror The effect of anion(Cl-) on the transition was studied. The relationship between aggregation and charge transfer was discussed and some explanations were given.

We proposed a new method to study adsorption dynamics by surface enhanced Raman scattering (SERS). A simple theortical model of adsoption dynamics for solid-liquid interfaces was established. We analysed the time dependence of SERS intensity and further deduced the parameter of adsorption dynamics, such as constant of adsorption speed, adsorption activation energy. As an example, we studied the adsorption dynamics of P-amino-benzoic acid adsorped on the silver colloid. The results show that the faster process of the time dependence of SERS are related to the adsorption process. From the experimental data and our theoretical model, the constant of adsorption speed were deduced. We believe that the study of adsorption dynamics by SERS is very promising.

Molecular fluorescence spectra of dye adsorbed on silver colliod and silver mirror were studied. Acriding Orange was used as sample in the experiment. We have found that the enhancement or quenching are depend on the competition of two processes, i.e., local field enhancement and non-radiation energy transfer from the molecule to metal surface. The fluorescence is enhanced when enhanced absorption and enhanced emission conditions are achieved. However, molecular fluorescence is far less enhanced then Raman. Theoretical calculation shows that peak enhencement of fluorescence intensity will be 10-102. It agrees with the experimental value for Acriding Orenge adsorbed on silver mirror.