Cited by 823
Tel Aviv University
Publishes on Advanced biosensing and bioanalysis techniques, DNA and Nucleic Acid Chemistry, Molecular Junctions and Nanostructures. 7 papers and 1.6k citations.
Add your photo, update your bio, and get notified when your ranking changes.
The fundamental mechanisms of charge migration in DNA are pertinent for current developments in molecular electronics and electrochemistry-based chip technology. The energetic control of hole (positive ion) multistep hopping transport in DNA proceeds via the guanine, the nucleobase with the lowest oxidation potential. Chemical yield data for the relative reactivity of the guanine cations and of charge trapping by a triple guanine unit in one of the strands quantify the hopping, trapping, and chemical kinetic parameters. The hole-hopping rate for superexchange-mediated interactions via two intervening AT base pairs is estimated to be 10(9) s(-1) at 300 K. We infer that the maximal distance for hole hopping in the duplex with the guanine separated by a single AT base pair is 300 +/- 70 A. Although we encounter constraints for hole transport in DNA emerging from the number of the mediating AT base pairs, electron transport is expected to be nearly sequence independent because of the similarity of the reduction potentials of the thymine and of the cytosine.
Hopping between bases of similar redox potentials is the mechanism by which charge transport occurs through DNA. This was shown by rate measurements performed with double strands 1-3. This mechanism explains why hole transfer displays a strong sequence dependence, and postulates that electron transfer in unperturbed DNA should not be dependent on the sequence.
Hole transfer through DNA is coupled with proton transfer processes.
In Hopping-Schritten zwischen Basen ähnlichen Redoxpotentials erfolgt der Ladungstransport durch DNA, wie Geschwindigkeitsmessungen an den Doppelsträngen 1–3 ergeben. Dieser Mechanismus erklärt, warum Lochtransfer stark sequenzabhängig ist, und postuliert, daß Elektronentransfer in ungestörter DNA nicht von der Sequenz abhängen sollte.