Surface-enhanced Raman spectroscopy of kojic acid on colloidal silver

CHED 1455

Caitlin D. Deane and Brian D. Gilbert, bgilber@linfield.edu. Department of Chemistry, Linfield College, McMinnville, OR 97128
The Raman spectra of solid kojic acid and the surface-enhanced Raman scattering (SERS) spectra of 3 mM kojic acid in colloidal silver nanoparticles over a pH range from 4.8 to 8.8 were measured. A DeltaNu 200A Raman spectrometer (633 nm excitation, 3 mW laser power) was used in all of the experiments. Gaussian XX was used to calculate vibrational frequencies for kojic acid using density functional theory at the B3LYP level with a 6-311G* basis set. The results of these calculations were used to make band assignments in the Raman and SERS spectra.