Abstract
DNA is one of the most promising molecules as the building bolcks in 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 in DNA-based electrochemical biosensors. The intrinsic electrical properties and actual nanostructures of polynucleotides, such as self-assembled DNA network and DNA films have been investigated using a nano-gap electrode and photoemission spectroscopy, SPM techniques, etc. Poly[d(G-C)]2, poly(dG)·poly(dC) constructs the uniform two-dimensional network structure on mica and SiO2/Si surfaces. The conductivity of these molecules has been successfully controlled by chemical doping. The dG-dC pairs provide conduction properties upon I2 doping while dA-dT pairs do not. It is found that the poly(dG)·poly(dC) may have hole conductivity. The conduction mechanism based on the charge hopping model is discussed.
