Adsorption of bombesin and its carboxyl terminal fragments onto the colloidal gold nanoparticles: SERS studies

Surface-enhanced Raman scattering (SERS) is a Raman spectroscopy technique often used to study processes occurring at a solid/liquid interface. In this work, SERS was used to investigate the adsorption of bombesin (BN) and its C-terminal fragments adsorbed onto colloidal gold nanoparticles. Briefly, the SERS results demonstrated that (1) the elongation of the C-terminal peptide fragment causes movement of the Met (l-methionine) side-chain in the direction of the gold nanoparticles and the weakening of the interactions between the amide bond and gold; (2) the His (l-histidine) residue assists in the peptides interaction with the gold nanoparticles; and (3) Trp (l-tryptophan) dramatically changes the SERS spectral pattern on gold.