Spectroscopic analysis of L-histidine adsorbed on gold and silver nanoparticle surfaces investigated by surface-enhanced Raman scattering.
The adsorption of l-histidine on gold (Au) and silver (Ag) nanoparticle surfaces has been comparatively analyzed by means of surface-enhanced Raman scattering (SERS). The SERS spectra of l-histidine on Ag were found to be quite different from those on Au, indicating dissimilar adsorption structures depending on metal substrates. Most peaks of l-histidine on Ag appeared to be due to coordination via the carboxylate (COO(-)) group with an imidazole ring of fairly upright geometry, whereas on Au it was assumed to adsorb with a rather flat geometry. A density functional theory (DFT) calculation was performed at the level of B3LYP/LANL2DZ to estimate the energetic stability of the binding of the imidazole ring and the carboxylate group of l-histidine with the Ag and Au atoms, respectively. Based on the DFT calculation, the carboxylate group of l-histidine was predicted to bind more favorably to Ag than to Au, and this was in line with our SERS spectral analysis.
Lim
Jong Kuk
JK
Department of Chemistry, Soongsil University, Seoul 156-743, Republic of Korea.
Kim
Youngmin
Y
Lee
So Yeong
SY
Joo
Sang-Woo
SW
D000327:Adsorption; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration
D012834:Silver; D006639:Histidine; D006046:Gold