SURFACE-ENHANCED RESONANCE RAMAN-SCATTERING EXCITATION PROFILES OF ANTHRACYCLINES ADSORBED ONTO SILVER PARTICLES

The surface-enhanced resonance Raman scattering (SERRS) spectra and excitation profiles of epirubicin and idarubucin have been obtained. The depolarization ratios and their frequency dispersion were also measured for some bands of epirubicin. Some bands of B1 species under the C2v symmetry or pseudosymmetry are active and become increasingly more prominent as the excitation frequency is moved to the red. The results indicate that the chromophore portion of the drug interacts edge-on with the Ag surface. Moreover, different peaks of Raman excitation profiles for the A1 and B1 modes have been found. Both peaks shift to the red by increasing the adsorbate concentration. The results have been discussed in terms of both the "electromagnetic" and the "charge-transfer-complex" approaches. It is shown that both models can furnish convenient and consistent interpretation of the experimental data. © 1990 American Chemical Society.