表面增强拉曼散射(SERS)活性基底的制备与优化对靶分子的研究非常关键.本文设计了一种二氧化硅—金核壳材料的SERS活性基底,通过调节二氧化硅—金种子和金生长溶液的比例调节二氧化硅球表面金纳米材料的厚度,得到一系列表面等离子体吸收带可调控的SERS活性基底.这类材料具有较宽的吸收带,适用于多激发线激发,并产生强烈的表面等离子体共振吸收峰.我们采用633 nm激发波长,选择苯硫酚作为探针分子研究基底的SERS活性,其SERS增强因子可以达到107.SERS的增强贡献主要来源于电磁场增强,而聚集在二氧化硅纳米粒子表面的金会提供巨大的电磁场,提高了基底的检测灵敏度和光谱重现性.这类基底在基于SERS应用方面具有潜在的应用价值.
In this paper,we prepared a Si O2@ Au nanoshell substrate for surface-enhanced Raman scattering study. In SERS-based study,SERS substrate was an important part for the determination of the target. By adjusting the proportional of Si O2@ Au and K-gold solutions to control the thickness of the gold shell which was covered on the Si O2 particles. UV-vis-NIR absorption spectrometer and SEM were employed to monitor the reaction process of the formation of Au on the surface of silica bead,and the optical resonance of the substrate could turn from visible to NIR area. It possessed the broad surface plasmon resonance,which extend the SERS applications with different laser excitations. To investigate the potential of this substrate for SERS applications,SERS spectra of thiophenol( TP) were normalized by using an internal standard of silicon( 520 cm- 1). The calculated enhancement factor( EF) of TP adsorbed onto a Si O2@ Au core-shell substrate was ~ 107following633 laser excitations. It could effectively control surface morphology of Si O2@ Au core-shell,which was one of the important factors in the fabrication of an excellent SERS-actived substrates. More importantly,this SERS substrate exhibited an excellent potential application in biosystem and environmental monitoring.