Acta Chimica Sinica ›› 2010, Vol. 68 ›› Issue (02): 107-114.     Next Articles

Full Papers

银电极表面异亮氨酸单分子膜结构和表面性质的表面增强拉曼光谱研究

曹晓卫*,钱庆庆,邓卫芹,张婷婷   

  1. (上海师范大学化学系 上海 200234)
  • 投稿日期:2009-05-21 修回日期:2009-08-05 发布日期:2010-03-17
  • 通讯作者: 曹晓卫 E-mail:xwcao@shnu.edu.cn
  • 基金资助:

    国家自然科学基金项目(20775049);上海市自然科学基金项目(06ZR14145);上海市教委基金项目(07ZZ67)

SERS Study of Structure and Surface Property of Self-assembled Monolayers of Isoleucine at Silver Electrode

Cao Xiaowei* Qian Qingqing Deng Weiqin Zhang Tingting   

  1. (Department of Chemistry, Shanghai Normal University, Shanghai 200234, China)
  • Received:2009-05-21 Revised:2009-08-05 Published:2010-03-17
  • Contact: CAO Xiao-Wei E-mail:xwcao@shnu.edu.cn

A surface-enhanced Raman scattering (SERS) technique was used to obtain the information about the characteristics of conformation and surface property of isoleucine self-assembled monolayers (SAM). SERS spectra of isoleucine SAM modified at electrochemically roughened silver surface were obtained when solution pH value or electrode potential was changed. The results reveal that isoleucine molecules were adsorbed mainly via the deprotonated carboxyl groups at the roughened silver electrode. This feature was not changed significantly with variation of the solution pH value. The surface acid-base property of the SAM was also analyzed and characterized by means of an SERS titration method. Perchlorate ion was used as a spectroscopic probe in the SERS titration. As for the influence of the electrode potential on the SAM, it is revealed that the isoleucine molecules were adsorbed via the deprotonated carboxyl groups and amino groups within the range of electrode potential in this research. Adsorption of these isoleucine molecules on Ag surface was changed obviously with the shift of electrode potential along the negative direction.

Key words: isoleucine, self-assembled monolayer, surface-enhanced Raman spectroscopy, pH value, electrode potential