氨基酸在银胶溶液中的表面增强拉曼效应

文章报道了通过制备合适的银胶盐纳米溶液 ,得到的甘氨酸、缬氨酸和赖氨酸在银胶溶液中的表面增强拉曼光谱。低波数 2 38cm-1谱带的出现 ,表明氨基酸分子已与银表面产生明显吸附。在所得SERS图谱中 ,表征C—C基团的 90 0～ 930cm-1谱带、表征NH2 基团的 110 0cm-1左右谱带和表征COO-基团的14 0 0cm-1附近的谱带振动都得到显著加强 ,其原因主要是通过羧基基团及氨基基团与银粒子表面产生吸附 ,增强机制属于化学增强 ,为短程效应。本实验中 ,当银胶溶液 pH值降低时 ,对拉曼散射的增强效果影响不大。

Surface-Enhanced Raman Scattering (SERS) of Amino Acids on Silver Colloid

The surface-enhanced Raman spectra of glycine, valine and lysine adsorbed on silver colloidal particles and the Raman spectrum of lysine in aqueous solution were obtained. The adsorption was accompanied by the appearance of the 238 cm -1 band corresponding to the oscillation of the molecule-metal chemical bond and indicating chemisorption of the amino acid. In the surface-enhanced Raman spectra of three amino acids, the peak bands at 900-930 cm -1, near 1 100 cm -1 and near 1 400 cm -1, corresponding to the carbon-carbon bond, carboxyl and amino group vibrations, respectively, were markedly increased on the silver colloidal particles. It means that the Raman spectra of polar groups such as COO-, NH 2 and C-COO- were strongly enhanced via the carboxyl group. There was no influence under the low pH condition in the experimental system used.