电流滴定法对两种短链分子自组装膜的研究  

Investigation of Self-assembled Monolayers of Two Short-chain Molecules by the Electrochemical Titration Method

作　　者：朱延松[1] 侯冬岩[1] 邵会波[2] 

机构地区：[1]鞍山师范学院化学系,鞍山114005 [2]首都师范大学化学系,北京100037

出　　处：《分析化学》2007年第2期201-205,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(No.29973026);教育部优秀青年教师资助计划;北京市教委项目资助

摘　　要：把带有—NH2的半胱胺和4-氨基硫酚两种短链分子组装到金电极上,形成自组装单分子膜;两种自组装膜在[Fe(CN)6]3-/4-溶液中进行循环伏安扫描时,出现了不同于长链分子自组装膜的行为:峰间距变窄、峰电流变大的现象,这是由于两者在金上组装不够致密,以及末端的—NH2存在对[Fe(CN)6]3-/4-的影响造成的。通过改变溶液的pH,研究溶液中H+浓度对半胱胺自组装膜和4-氨基硫酚自组装膜在[Fe(CN)6]3-/4-溶液中电化学行为的影响;通过电流滴定的方法求算出半胱胺自组装膜和4-氨基硫酚自组装膜的表面pKb分别为2.4±0.2和4.7±0.2;通过在碱性条件下的循环伏安图,对两者的组装效果进行了比较。Two short-chain molecules of cysteamine and 4-aminothiophenol were modified on gold electrode by self-assembled monolayers（SAMs） , when they were studied by cyclic voltammetry, it was found that peak current increased and the peak separation decreased. The reason was that the coverage of two modified electrodes was not compacted and [ Fe（CN）6 ]^ 3-/4- was affected by end group --NH2 of cysteamine and 4-amion-thiophenol. The electrochemical behavior of two modified electrodes was studied in [ Fe（CN） 6 ]^ 3-/4- solution at different pH. The surface pKb of the self-assembled monolayers of cysteamine and 4-aminothiophenol was estimated to be 2.4 ± 0.2 and 4.7 ± 0.2 respectively by the electrochemical titration method. The coverage of two modified electrodes was compared by cyclic vohammograms in alkaline solution.

关 键 词：半胱胺 4-氨基硫酚 自组装单分子膜 电流滴定 

分 类 号：O657.1[理学—分析化学]