Study on the Character and Structure of 2,2’-cyanine and 1-ethyl-3’-methyl-2-thiacyanine Iodide and Interaction between the Dye and AgCl Colloids by SERRS

We have for the first time recorded and compared SERS and SERRS of 1,1’-diethy-2,2’-cyanine iodide and 1-ethyl-3’-methyl-2-thiacyanine iodide dyes both in monomer and in J-aggregate state adsorbed on AgCl colloids when laser wavelength is 632.8, 570.0nm for the former and 514.5 and 488.0 nm for the both. The character and structure of the adsorbate and interaction between the dyes and AgCl colloids have been discussed in this paper, we have also discussed the connection between SERS and spectral sensitization in photographic process and explained the enhanced mechanism. SERRS can be a powerful means for studying in-situ adsorption of dye moleculecules on-to silver halide grains.