金电极上6-巯基嘌呤自组装单分子膜的拉曼映射及原位表面增强拉曼光谱电化学研究。

Raman mapping and in situ SERS spectroelectrochemical studies of 6-mercaptopurine SAMs on the gold electrode.

作者信息

Yang Haifeng, Liu Yanli, Liu Zhimin, Yang Yu, Jiang Jianhui, Zhang Zongrang, Shen Guoli, Yu Ruqin

机构信息

State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.

出版信息

J Phys Chem B. 2005 Feb 24;109(7):2739-44. doi: 10.1021/jp046082l.

DOI:10.1021/jp046082l

PMID:16851282

Abstract

The self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) were formed at the roughened polycrystalline gold surfaces in acid and alkaline media. The time-dependent Raman mapping spectral analysis in conjunction with the quantum calculations for the vibrational modes using ab initio BLYP/6-31G method suggested that both of the resulted 6MP SAMs adopted the same adsorption mode through the S atom of pyrimidine moiety and the N7 atom of the imidazole moiety anchoring the gold surface in a vertical way. The in situ surface-enhanced Raman scattering spectroelectrochemical experiment was conducted to examine the stability of the SAMs at various bias potentials. It was found that the detaching process of the 6MP SAMs from the surface involved one electron reduction as the voltage was applied at ca. 0.7 V vs a standard calomel electrode.

摘要

6-巯基嘌呤（6MP）的自组装单分子层（SAMs）在酸性和碱性介质中的粗糙多晶金表面形成。结合使用从头算BLYP/6-31G方法对振动模式进行的量子计算，进行随时间变化的拉曼映射光谱分析，结果表明，两种生成的6MP SAMs都通过嘧啶部分的S原子和咪唑部分的N7原子以垂直方式锚定在金表面，采用相同的吸附模式。进行原位表面增强拉曼散射光谱电化学实验，以研究SAMs在各种偏置电位下的稳定性。结果发现，当相对于标准甘汞电极在约0.7 V施加电压时，6MP SAMs从表面的分离过程涉及单电子还原。