作　　者： (李盼）; (聂永惠）; (滕渊洁）; (刘文涵）;

机构地区： 浙江工业大学化学工程学院绿色化学合成技术国家重点实验室培育基地,浙江杭州310032

出　　处： 《发光学报》 2017年第9期1233-1239,共7页

摘　　要： 采用化学还原法制备了以Au为核、包覆Ag的双金属核壳Au@Ag纳米粒子,并成功地用于表面增强拉曼光谱(SERS)分析测试。通过改变制备液中Ag/Au的量比来调控Ag壳包覆厚度。采用透射电子显微镜(TEM)和紫外-可见光谱仪(UV-Vis)对Au@Ag纳米粒子的构貌进行表征。TEM显示明显存在核壳结构,且Ag壳层随Ag/Au的量比的增加而逐渐变厚;UV-Vis表明随着Ag/Au的量比的增加,Au@Ag纳米粒子出现了Au核与Ag壳吸收峰的2个等离子体共振峰,同时伴随着Au峰的蓝移和Ag峰的红移。以双甲脒为分析物,考察了不同Ag/Au的量比时的Au@Ag纳米粒子的SERS活性。结果表明,SERS活性随Ag/Au的量比的增加先增大后减小,在6∶5时其SERS增强效应最佳,此时Ag壳厚度约为6 nm。以对巯基苯胺(4-ATP)、结晶紫(CV)和双甲脒为分析测试对象,对比了Au@Ag、Ag、Au 3种基底的SERS活性。结果表明,所制备的Au@Ag纳米粒子的SERS活性要明显优于单纯的Au、Ag纳米粒子。 Au@Ag core-shell bimetallic nanoparticles were prepared by chemical reduction method and successfully applied to surface-enhanced Raman scattering（ SERS） analysis. The thickness of the coated Ag shell is regulated by changing the Ag/Au molar ratios in the preparation solution. The morphology of the Au@Ag nanoparticles were characterized by TEM and further confirmed by UVVis. TEM spectra show that Au @Ag nanoparticles have obvious core-shell structure,and the Ag shell layer becomes thicker with the increasing of Ag/Au molar ratio. UV-Vis spectra show that Au@Ag nanoparticles exhibit two plasmon resonance absorption peaks assigned to Au and Ag plasmonic absorption. When Ag/Au molar ratio increases,the Au core resonance is blue-shifted and the Ag shell resonance is red-shifted. The enhanced effects of Au@Ag nanoparticles with different Ag/Aumolar ratios in SERS were investigated by using amitraz as a probe. It is found that the SERS intensity of amitraz is enhanced firstly and then becomes weaker with the increasing of Ag/Au molar ratios,The optimum SERS signal appeares when the Ag/Au molar ratio is 6∶5 and the thickness of Ag shell is 6 nm. Moreover,the SERS effects of Au@Ag,Ag and Au nanparticles were further compared by using p-mercaptoaniline（ 4-ATP）,crystal violet（ CV） and amitraz as analytes. The results show that the SERS effect of Au@Ag nanoparticles is obviously stronger than that of pure Au or Ag nanoparticles.

关 键 词： 纳米粒子 表面增强拉曼光谱