银纳米颗粒通过自组装形成二维结构薄膜具有独特的光学性质, 其提供的大量“热点”使其成为优越的表面增强拉曼散射(Surface enhanced Raman Scattering, SERS)基底。本文采用水／正己烷界面上自组装的方法得到了由密排的银纳米颗粒构成的薄膜, 并以Rhodamine 6G为探针分子, 比较了不同尺寸银颗粒组成薄膜的增强效果, 结果表明160 nm颗粒的增强效果最佳; 而与通过滴加银溶胶后形成的稀疏颗粒薄膜相比, 密排颗粒薄膜的SERS增强效果明显更好。

Two dimensional nanostructures film silver nanoparticles (NPs) formed through self-assembly method exhibit an unique optical property, including extraordinarily offering large amounts of “hot spots”, which make them ideal candidate of surface-enhanced Raman scattering substrate. In this paper, large-area Ag films composed of close-packed NPs were fabricated by taking advantage of self-assemble at heptanes/water interface. Using Rhodamine 6G(R6G) as probing molecules, the SERS characteristic of the films composed of silver NPs with variant sizes was exploited. It is found that films with Ag size of 160 nm exhibited optimal enhancement effect. Moreover, the films made of closely-packed NPs unambiguously showed much enhancement than the films composed of sparse ones by simply dropping Ag sols.