Abstract
DNA is one of the most promising molecules as the scaffold for molecular nanotechnology and nanoelectronics. The investigations of DNA on the nanostructure, electrical conductivity and electronic states have significant implications for the application of DNA in electronic devices and m DNA based electrochemical biosensors. The direct measurements of the intrinsic electrical characteristics of polynucleotides using a conducting probe atomic force microscope have been performed using self-assembled DNA network. Poly[d(G-C)]_2 and poly(dG)・poly(dC) construct the uniform two-dimensional reticulate structure and show the p-type rectified behaviors in the atmospheric condition, presumably due to the different redox potentials of DNA bases. The conductivity of these molecules has DNA been successfully controlled by chemical doping. It is found that the poly(dG) 'poly(dC) has the best conductivity and can act as a conducting nanowire. The conductive mechanism is discussed by the charge hopping model based on the SPM observation of DNA nanostructure.
