Diluting thiol-derivatized oligonucleotide monolayers on Au(111) by mercaptohexanol replacement reaction

被引：13

作者：

Song, Yonghai ^{[1
]}

Liu, Yaqing ^{[1
]}

Yang, Menglong ^{[1
]}

Zhang, Bailin ^{[1
]}

Li, Zhuang ^{[1
]}

机构：

[1] Chinese Acad Sci, Changchun Inst Appl Chem, Grad Sch, State Key Lab Electroanalyt Chem, Changchun 130022, Peoples R China

来源：

APPLIED SURFACE SCIENCE | 2006年 / 252卷 / 16期

基金：

中国国家自然科学基金;

关键词：

electrochemistry; scanning tunneling microscopy; DNA; surface; monolayers;

D O I：

10.1016/j.apsusc.2005.07.044

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Surface replacement reaction of thiol-derivatized, single-stranded oligonucleotide (HS-ssDNA) by mercaptohexanol (MCH) is investigated in order to reduce surface density of the HS-ssDNA adsorbed to Au(111) surface. Cyclic voltammograms (CVs) and scanning tunneling microscopy (STM) are employed to assess the composition and state of these mixed monolayers. It is found that each CV of mixed self-assembled monolayers (SAMs) only shows a single reductive desorption peak, which suggests that the resulted, mixed SAMs do not form discernable phase-separated domains. The peak potential gradually shifts to negative direction and the peak area increases step by step over the whole replacement process. By analyzing these peak areas, it is concluded that two MCH molecules will replace one HS-ssDNA molecule and relative coverage can also be estimated as a function of exposing time. The possible mechanism of the replacement reaction is also proposed. The DNA surface density exponentially reduces with the exposing time increasing, in other words, the replacement reaction is very fast in the first several hours and then gradually slows down. Moreover, the morphological change in the process is also followed by STM. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：5693 / 5699

页数：7

共 33 条

[1] DNA Electrochemistry as a probe of base pair stacking in A-, B-, and Z-form DNA [J].