不同环境条件下金属离子对单个DNA分子电导率和结构的影响

Effects of Metal Ions on Conductivity and Structure of Single DNA Molecule in Different Environmental Conditions.

作者信息

Dong Ruixin, Yan Xunling, Li Ke, Ban Ge, Wang Minghong, Cui Shouxin, Yang Bing

机构信息

School of Physics Science and Information Technology, Liaocheng University, 252059 Liaocheng Shandong, People's Republic of China.

出版信息

Nanoscale Res Lett. 2010 Jun 4;5(9):1431-1436. doi: 10.1007/s11671-010-9657-3.

DOI:10.1007/s11671-010-9657-3

PMID:20730127

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2920413/

Abstract

We design a novel nano-gap electrode to measure the current of DNA molecule, by which the current-voltage characteristics of individual native DNA, Ag-DNA and Ni-DNA molecules are obtained, respectively. The results show that the voltage gap of Ag- and Ni-DNA is higher than that of native DNA, and the conductance is lower than native DNA in neutral environment. The structure transition from B- to Z-DNA is observed in the presence of high concentrations of nickel ions and Ag-DNA appears chaos state by STM image and U-V spectra characterization. But in alkaline environment, the conductance of Ni-DNA rises and the voltage gap decreases with the increasing of nickel ion concentration denotes that the conductive ability of Ni-DNA is higher than that of native DNA.

摘要

我们设计了一种新型纳米间隙电极来测量DNA分子的电流，通过该电极分别获得了单个天然DNA、银-DNA和镍-DNA分子的电流-电压特性。结果表明，在中性环境中，银-DNA和镍-DNA的电压间隙高于天然DNA，且电导率低于天然DNA。在高浓度镍离子存在的情况下观察到了从B型到Z型DNA的结构转变，并且通过扫描隧道显微镜（STM）图像和紫外光谱表征表明银-DNA呈现混沌状态。但在碱性环境中，镍-DNA的电导率随镍离子浓度的增加而升高，电压间隙减小，这表明镍-DNA的导电能力高于天然DNA。