二维组装纳米银粒子上对巯基苯胺的表面增强拉曼光谱研究

Surface-enhanced Raman Spectroscopic Study of P-aminothiophenol on Nanosized Silver Particles Assembled in Two-dimensional Structure

采用表面自组装方法在聚赖氨酸修饰ITO电极表面和对巯基苯胺修饰光滑银表面组装了纳米银粒子的二维结构。FT -SERS光谱结果表明 ,巯基苯胺的吸附取向垂直于金属银表面 ,其中电磁增强机理起主导作用 ,但同时也存在化学增强的贡献。纳米银粒子的“体积效应”使其与吸附分子间的电荷转移更为有利。耦联于纳米银和光滑银表面间的巯基苯胺的拉曼散射增强则与纳米银粒子和光滑银表面的耦合而导致的局部电磁场增强直接相关。

By self-assembly method, nanosized silver particles were assembled on the ITO surface modified with poly-L-lysine and smooth silver surface modified with p-aminothiophenol. The adsorbed p-aminothiophenol adopts a perpendicular orientation relative to the metal surface, and surface-enhancement effect mainly comes from electromagnetic enhancement mechanism with a minor contribution from chemical enhancement. On the other hand, the enhancement of Raman scattering of p-aminothiophenol coupled between silver nanosized particle and smooth silver surface is ascribed to the enhancement of local electromagnetic field via an electromagnetic coupling between nanosized silver particle and smooth silver surface.