Mechanisms for DNA Charge Transport

Some of the critical characteristics of DNA charge transport (CT) chemistry were studied. Among the most interesting characteristics of charge transport in DNA is the long distance over which it occurs. It is notable that initial measurements of DNA-mediated charge transport for both photooxidation experiments and device experiments found rates and conductivities spanning several orders of magnitude over comparable distances, depending on the experimental conditions. The structure of DNA is central to its extraordinary effectiveness as the genetic template for the cell. The ionic strength can dictate the conformation of DNA. A high ionic strength drives the transition from the B-form to the more extended Z-form of DNA. Poor base stacking, associated with this condensed structure, leads to less efficient DNA-mediated CT. In addition to global changes in structural integrity, subtle modulations to structure can also have profound effects on the rates and yields of DNA-mediated CT. It is clear that DNA, when adequately coupled between the donor and acceptor, can competently mediate CT over long distances.