Surface Enhanced Raman Scattering studies of l-amino acids adsorbed on silver nanoclusters

Silver nanocluster films were prepared using plasma inert gas phase condensation technique. These were used as Raman active substrates for Surface Enhanced Raman Scattering (SERS) studies of 19 standard l-amino acids adsorbed on the surface of Ag nanoclusters via AgN bonds. A detailed study of two essential aromatic amino acids viz. l-Phenylalanine and l-Tryptophan showed a correlation between the Raman intensity of the characteristic lines of phenol and indole side chains and their molar concentrations in the range 1 μM–1 mM. This indicates that Raman studies can be used for quantitative determination of the amino acids in proteins.