金纳米粒子组装体系中偶联单分子层膜结构的SERS光谱表征与分析  

SERS Spectroscopic Characterization and Analysis of the Molecular Structure of Linkage Monolayers in Assembled Gold Nanoparticle Films

作　　者：曹晓卫[1] 刘文华[1] 李欣然[1] 王荣[1] 吴霞琴[1] 

机构地区：[1]上海师范大学化学系,上海200234

出　　处：《物理化学学报》2011年第7期1600-1608,共9页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20775049;20973114)资助项目~~

摘　　要：通过分子自组装方法制备4,4'-二硫联吡啶(PySSPy)单分子膜修饰的金电极.利用所形成的对巯基吡啶自组装单分子膜(SAMs)作为偶联层进行金纳米粒子有序膜的组装.对该纳米粒子组装体系进行Raman光谱测定,得到了具有良好信噪比的对巯基吡啶单分子膜的表面增强拉曼散射(SERS)光谱.在此基础上,进一步采用电化学现场SERS光谱技术研究了该纳米粒子组装体系的SERS光谱随电位变化的规律.在该体系稳定的电位范围内表征对巯基吡啶单分子膜的特征谱峰1011与1093 cm^(-1)、1575与1610 cm^(-1)以及1206与1215cm^(-1)这三对谱峰其强度随着所施加电位的改变呈现出明显的规律性.分析表明,偶联单分子层中吡啶环芳香性随着所施加电位的改变而有规律地变化是SERS光谱特征改变的内在原因.Molecular assembly was used to prepare a 4,4＇-dithiodipyridine （PySSPy） self-assembled monolayers （SAMs） modified gold electrode. The prepared PySSPy SAMs modified on gold electrode were then used as linkage monolayers to fabricate gold nanoparticle assembled films. In our research, surfaceenhanced Raman scattering （SERS） technique was used to investigate the structural characteristics of the linkage monolayers. Moreover, electrochemical in situ SERS spectroscopy was used to characterize the effect of electrode potential on the molecular structure of this linkage monolayer. An analysis of the regular variations in intensities and shifts of the characteristic Raman peak pairs related to the adsorbed molecules in this linkage monolayer, such as at 1011 and 1093 cm^-1, 1575 and 1610 cm^-1, 1206 and 1215 cm^-1, revealed that the aromaticity of the pyridyl ring groups in the linkage monolayer changed with the applied electrode potential. The results show that the adsorbed molecule exists mainly in the form of a thiol tautomer in the negative potential range while it exists mainly in the form of a thione tautomer in the positive potential range.

关 键 词：金纳米粒子 纳米粒子有序膜 4 4’-二硫联吡啶 自组装单分子膜:表面增强拉曼散射光谱:电极电位 

分 类 号：O614.123[理学—无机化学]