Prof. Sven Stafström, Linköping University

Electron localization and charge transport in DNA

Long distance charge transfer, or charge transport, in DNA is of great importance both for the function of DNA during oxidative stress and for the potential use of DNA in
molecular-scale electronic devices. Charge transport is made possible due to the electronic overlap between the base-pairs along the DNA strand. However, due to the different eigen-energies of the relevant molecular orbitals of the guanine, cytosine, adenine and thymine nucleotides, the DNA strand can be considered as a disordered system in which the states are localized. Using the method of transfer matrices we have calculated the localization length in λ-DNA and found that the electronic states are localized to individual nucleotides. Based on the derived electron localization lengths we have used a Monte Carlo approach to simulate hopping transport between these localized states. From these simulations we obtain a detailed picture of how the transfer rate varies with temperature and applied electric field strength. We can also present details of the transport, for instance the average hopping distance and which nucleotides that are involved in the transport process.

For more information contact Dr. Jean-Luc Brédas (404-385-4986).