【摘要】 用紫外 -可见两步光化学还原法 ,合成了等离子体共振峰出现在近红外区的新型绿色银胶 .首次用该银胶作为基底研究人血清白蛋白 (HSA)的近红外表面增强拉曼散射 (NIR SERS) ,发现银胶中的线状银纳米粒子聚集体有较强的NIR SERS效应和生物兼容性 ,这为研究生物大分子的结构、构象和界面作用提供了一种较为理想的活性基底 .由所得到的NIR SERS光谱可发现 ,吸附在银纳米粒子表面的HSA的肽链骨架仍以α 螺旋结构为主 ,其二级构象特征基本不变 ;吸附作用诱导部分芳香氨基酸残基所处的微环境发生改变 ,趋于银纳米粒子表面 .此外 ,明显观察到COO-与C—S的特征谱带说明HSA中去质子的羧基氧、二硫桥键的硫直接与银纳米粒子表面作用 .更多还原

【Abstract】 A novel colloid was synthesized using a two step photoinduced reducting method with irradiation of ultraviolet and visible light. Characterized by a surface plasmon band in the near infrared wavelength range, the linear nanoparticle aggregations in the silver colloid was found to occur with high efficient near infrared surface enhanced Raman scattering (NIR SERS) effect and high biocompatibility for human serum albumin (HSA), which provides a potential active substrate for investigating the structure, conformation and interfacial interactions of bio macromolecules. For the adsorbed HSA, the obtained NIR SERS spectrum indicates that the majority of peptide back bone adopts an α helical structure, which keeps the native conformational characteristic of normal HSA, the microenvironments of some aromatic amino residues are induced to approach the surface of silver nanoparticles. In addition, the detected Raman shifts for COO - and C─S provide evidences that deprotonated carboxyl oxygen atoms and sulphur atoms in the disulfide bridges have the direct interfacial interactions with the silver nanoparticles.更多还原