Mechanisms of charge carrier generation in polycrystalline DNA fibers

Abstract

The first determination of the valence electron structure of an infinite three-dimensional DNA fiber (in the all-atom representation, together with its hydration shell and sodium counterions) is reported within the tight-binding approximation. The present results suggest that actual DNA fibers are disordered systems on the verge of their metal–insulator transition, with irregularities of DNA conformation being much more important for DNA electrical properties than aperiodicity of the DNA base sequence alone. Possible mechanisms of charge carrier self-generation in DNA are discussed on the basis of semiempirical quantum-chemical calculations.