金纳米粒子组装体系的表面增强拉曼光谱特性研究——表面粒子密度与拉曼光谱强度的关系

利用纳米粒子组装制备了金基底———巯基苯胺自组装膜偶联层———金纳米粒子的“三明治”结构，研究了表面粒子密度与偶连层分子的拉曼光谱强度的关系。实验结果显示，该结构对偶连层分子的拉曼光谱有很好的增强效应，增强因子可达１０５。在表面粒子密度较低时，拉曼光谱强度与表面粒子密度曲线呈线形，随着表面粒子密度的增加，曲线出现负偏差并在粒子密度较高区域出现一个平台。

Dependence of the Raman Intensity on the Surface Coverage of Nanoparticles in a SERS Active Gold Nanoparticulate Film

The relationship between the surface coverage of nanoparticles and the intensity of surface enhanced Raman scattering(SERS) in a two dimensional gold nanoparticulate film was studied. Strong enhancement was observed which is due to the nanoparticle substrate electromagnetic coupling and the contribution of chemical enhancement. It was found that SERS intensity increases linearly at lower coverage, then negatively deflected from the initial line, and finally reach a plateau at increased coverages. We attributed it to the absorption and scattering caused by the neighboring nanoparticles.