Effects of Metal Ions on Conductivity and Structure of Single DNA Molecule in Different Environmental Conditions
School of Physics Science and Information Technology, Liaocheng University, 252059, Liaocheng Shandong, People’s Republic of China
Nanoscale Research Letters 2010, 5:1431-1436 doi:10.1007/s11671-010-9657-3Published: 4 June 2010
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.