应用化学 ›› 2010, Vol. 27 ›› Issue (08): 970-977.DOI: 10.3724/SP.J.1095.2010.90772

• 研究论文 • 上一篇    下一篇

巯基修饰单链DNA在纳米金薄膜电极上自组装、杂交和取向的电化学交流阻抗谱

魏旭,郝青丽*,陆路德,汪信,杨绪杰   

  1. (南京理工大学材料化学实验室 南京 210094)
  • 收稿日期:2009-11-23 修回日期:2009-12-29 出版日期:2010-08-10 发布日期:2010-08-10
  • 通讯作者: 郝青丽,女,博士,副教授; E-mail:haoqingli@yahoo.com; 研究方向:功能材料与电化学
  • 基金资助:
    江苏省科技支撑计划(BE2009159,BK2006201)和南京理工大学卓越计划紫金之星(2008)资助项目

Electrochemical Impedance Spectroscopy Study on SH-ssDNA Self-Assembling, Hybridization and Orientation on Thin-film Nana-gold Electrode

WEI Xu, HAO Qing-Li*, LU Lu-De, WANG Xin, YANG Xu-Jie   

  1. (Materials Chemistry Laboratory,Nanjing University of Science & Technology,Nanjing 210094)
  • Received:2009-11-23 Revised:2009-12-29 Published:2010-08-10 Online:2010-08-10

摘要:

利用电化学交流阻抗技术对SH-ssDNA在纳米金薄膜电极表面的自组装、杂交和取向进行了系统表征。 探讨了SH-ssDNA的组装时间、浓度和链长对其自组装的影响,自组装15 h时电荷传递电阻Rct最大,表面覆盖率最高;研究了SH-ssDNA的浓度、链长以及与互补DNA的杂交方式对杂交反应的影响。 结果发现,随着单链浓度的增加,杂交后Rct的变化值逐渐降低,当SH-ssDNA为5 μmol/L时Rct值比杂交前增加了16%。 通过对阻抗谱数据模拟和分析,表明SH-ssDNA以垂直竖立取向在金电极表面形成均匀致密单分子层,杂交效率与SH-ssDNA的覆盖率密切相关。

关键词: 交流阻抗谱, SH-ssDNA, 自组装, 杂交, 取向

Abstract:

The self-assembling, hybridization and orientation of SH-ssDNA on the surface of thin-film nano-gold electrodes were characterized systematically by means of the electrochemical impedance technique. The effects of assembling time, concentration and the length of SH-ssDNA on its self-assembling were investigated. The Rct and surface coverage reached the highest values when assembling time was 15 h. The influences of the concentration and length of SH-ssDNA and its hybridization method with complementary DNA on the hybridization reaction were also studied. The result shows the change of Rct decreases with the increase of the SH-ssDNA concentration. The Rct was increased by 16% when the concentration of SH-ssDNA was 5 μmol/L. The data simulation and analysis of impedance spectroscopy indicated that a unique self-assembled monolayer of SH-ssDNA was formed with an upright orientation on the nano-Au electrode surface. The result shows the hybridization efficiency is closely associated with the coverage of SH-ssDNA.

Key words: Electrochemical Impedance Spectroscopy, SH-ssDNA, Self-Assembling, Hybridization, Orientation

中图分类号: