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利用纳米粒子组装技术制备出金基底/巯基苯胺自组装膜偶联层/金纳米粒子的“三明治”结构.实验结果显示 ,该结构对偶联层分子的喇曼光谱显示出很好的增强效应 ,增强因子可达105 ;在表面粒子密度(粒子覆盖度)较低时 ,表面增强喇曼散射(SERS)强度与表面粒子密度近似呈线性关系 ,随着表面粒子密度的增加 ,这种线性关系出现负偏差并在表面粒子密度较高区域出现一个平台 ;在60 -110nm范围内大粒径金粒子对喇曼光谱的增强效果强于小粒径金粒子.高增强因子出现的原因是体系中存在化学增强效应以及纳米粒子与金基底之间的电磁偶合作用 ,初步解释了喇曼强度随粒子密度的变化规律.
The “sandwich” structure of the gold / PGA / gold nanoparticles was prepared by nanoparticle assembly technique.The experimental results show that Raman spectra of the conjugated layer molecules show a good enhancement effect, The enhancement factor can reach 105. When the surface particle density (particle coverage) is low, the surface-enhanced Raman scattering (SERS) intensity is approximately linear with the surface particle density. With the increase of surface particle density, this linear relationship appears Negative deviation and a plateau in the region with high surface particle density.The enhancement of Raman spectrum of large-size gold particles in the range of 60-110nm is stronger than that of small-size gold particles.The reason for the high enhancement factor is the existence of the system Chemical strengthening effect and the electromagnetic coupling between the nanoparticles and the gold substrate, the law of Raman intensities with particle density is preliminarily explained.