金核银壳纳米粒子薄膜的制备及SERS活性研究

采用柠檬酸化学还原法制备金溶胶, 通过自组装技术在石英片表面制备金纳米粒子薄膜, 在银增强剂混合溶液中反应获得金核银壳纳米粒子薄膜. 用紫外-可见吸收光谱仪和原子力显微镜(AFM)研究了不同条件下制备的金核银壳纳米粒子薄膜的光谱特性和表面形貌, 并以结晶紫为探针分子测量了金核银壳纳米粒子薄膜的表面增强拉曼光谱(SERS). 结果表明, 金纳米粒子薄膜的分布、银增强剂反应时间的长短对金核银壳纳米粒子薄膜的形成均有重要影响. 制备过程中, 可以通过控制反应条件获得一定粒径的、具有良好表面增强拉曼散射活性的金核银壳纳米粒子薄膜.

Preparation of Au Core-Ag Shell Nanoparticles Film and Its SERS Activity Study

Gold colloids prepared through chemical reduction were self-assembled on the surface of quartz slide to form Au colloidal films. The obtained Au colloidal films were immersed into the mixture of silver enhancer and initiator to fabricate Au core-Ag shell nanoparticles films. The optical characteristics and surface morphology of Au core-Ag shell nanoparticles films prepared under different conditions were characterized by means of UV-Vis spectroscopy and atomic force microscopy. The performance of these Au core-Ag shell nanoparticles films used as SERS-active substrates was evaluated using crystal violet as a molecular probe by the measurement of corresponding surface enhanced Raman spectrum(SERS). It was found that both the distribution of Au colloidal particles on the surface of quartz and the reaction time significantly influence the formation of Au core-Ag shell nanoparticles films. The research results indicate that the Au core-Ag shell nanoparticles film with suitable particles size and good SERS activity can be obtained by controlling the reaction condition.