不同形貌金纳米粒子的制备及其表面增强拉曼散射效应的研究

不同形状的金纳米粒子在表面增强拉曼散射(surface enhanced Raman scattering,SERS)中有不同的增强效果,多面体金纳米粒子具有多角结构,显示出比金纳米板更为明显的增强效果,近年来对其合成和性质的研究备受关注。该研究探究了十二面体,二十面体,三角板,球形四种形状的金纳米粒子在SERS中不同的增强效果。分别采用硼氢化钠还原法和以N,N-二甲基甲酰胺(DMF)为还原剂制备金三角纳米片和二十面体金纳米粒子,又以二十面体金纳米粒子为种子制备出十二面体金纳米粒子,并分别以以上三种不同形貌的金纳米粒子及球形金溶胶为基底,4-巯基吡啶,对巯基苯甲酸为探针分子检测了其在不同激发波长下的增强效果。透射电子显微镜结果表明金三角纳米板的平均边长为130nm,二十面体和十二面体金纳米粒子的粒径分别为100和120nm。三者的紫外可见吸收峰分别在589,598和544nm处。表面增强拉曼散射结果表明金多面体比金三角纳米板表现出更好的增强效果。

Preparation of Au Nanoparticles with Different Morphologies and Study of Their Property as Surface Enhanced Raman Scattering Substrates

Different shapes of gold nanoparticles (NPs)have different enhancement effect in Surface Enhanced Raman Scattering (SERS).The polyhedral Au NPs have multiple angular structures,which show stronger enhancement effect than Au nanoplate-lets.In recent years,the research on synthesis and properties of polyhedral Au NPs has attracted much attention.In this study the enhancement effect of the Au NPs in SERS was observed in Au NPs with the shape of dodecahedron,icosahedron,triangular plate and spherosome.Triangular Au NP films were prepared through a chemical reduction method using sodium borohydride as the reductant.As for synthesizing icosahedral Au NPs,Poly (vinyl pyrrolidone)is used as a capping agent and diethylene glycol is used as a reducing agent.Dodecahedral Au NPs were synthesized using icosahedral Au NPs as seeds.SERS spectra were de-tected for these three Au NPs as well as the traditional colloidal Au by using 4-mercaptopyridine and 4-mercaptobenzoic as pro-bing molecules.Triangular Au NP films,icosahedral Au NPs and dodecahedral Au NPs were with average diameters of about 130,100 and 120 nm.UV/Vis spectroscopy indicated that these three Au NPs had typical absorbance bands at 589,598 and 544 nm.The results show that the Au polyhedron has better enhancement ability than the Triangular NPs.