Gold nanoparticles were homogeneously coated with silica using the silane coupling agent (3-aminopropyl)-trimethoxysilane to functionalize the gold surface and sodium silicate solution as the precursor of silica. The shell thickness could be well controlled by changing the amount of sodium silicate, reaction temperature and time. The Au@SiO2 core-shell nanoparticles with a suitable silica shell thickness exhibited optimal SERS activity and were self-assembled onto an ITO substrate in order to get a stable and reproducible SERS substrate. The conditions for preparing SERS substrates can be optimized by investigating the relationship between the intensity of SERS signals and the thickness of silica shell. The reproducible SERS measurements were performed by using 1,4-BDT and 4,4'-bipyridine as probe molecules. Within a certain concentration range, the linear relationship between the SERS intensities and the logarithm of concentration was obtained. The results revealed that the Au@SiO2 substrate assembled on ITO surface could be developed as a reproducible substrate for the quantitative analysis.%以氨基硅烷为偶联剂,硅酸钠为硅源,合成了一种以金为核,二氧化硅为壳的核壳纳米粒子.通过调节硅酸钠的量,反应温度和反应时间控制二氧化硅壳层厚度,获得理想的表面增强效应.通过研究表面增强拉曼光潜(SERS)信号强度和二氧化硅层厚度之间的关系优化基底的制备条件.采用对巯基苯和联吡啶作为探针分子进行 SERS 实验,在一定浓度范围内得到 SERS 信号强度和浓度的对数之间的线性关系,实验结果表明此组装有 Au@SiO2 的 ITO 基底作为可循环利用基底可定量分析吸附物种的浓度.
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