Quantum Transport in DNA-based Molecular Wires

Prof. Dr. Gianaurelio Cuniberti, Dresden University of Technology [Homepage]

Prof. Dr. Marcus Elstner, University of Karlsruhe [Homepage]

Despite great efforts in the experimental and theoretical investigation of DNA charge migration,
no unified explanation of the microscopic mechanisms governing charge transfer/transport has been
achieved up to date. The complexity of this bio-molecule as well as the variety of factors which may
influence charge transfer/transport (solvent, base dynamics, base sequence, metal-molecule contact)
make the existing experimental studies very difficult to analyze. Thus, theory plays a prominent role
by guiding experimental studies and providing them with well-defined predictions concerning the role
of all these factors. In the previous granted phase of this proposal, we have developed a computational
scheme which allows to obtain effective electronic coupling parameters with a comparable accuracy
to that of ab initio approaches. Moreover, we also can include in a straightforward way dynamical
effects –arising either from the internal base-pair dynamics or from the presence of a solvent– into the
electronic parameters. Within the current proposal, we plan to pursue this research and formulate
–relying on the previous results– coarse-grained models for charge transport through DNA. Our focus
will be first the paradigmatic double-strand structure, but in a later phase of the project we will
address in detail the properties of DNA-derivatives, especially G4-DNA and X-DNA, structurally and
thermodynamically more stable than dsDNA and may thus be better candidates for an employment
in molecular electronic devices.