Abstract

Charge transport in molecular systems, including DNA, is involved in many basic chemical and biological processes, and its understanding is critical if they are to be used in electronic devices. This important phenomenon is often described as either coherent tunnelling over a short distance or incoherent hopping over a long distance. Here, we show evidence of an intermediate regime where coherent and incoherent processes coexist in double-stranded DNA. We measure charge transport in single DNA molecules bridged to two electrodes as a function of DNA sequence and length. In general, the resistance of DNA increases linearly with length, as expected for incoherent hopping. However, for DNA sequences with stacked guanine-cytosine (GC) base pairs, a periodic oscillation is superimposed on the linear length dependence, indicating partial coherent transport. This result is supported by the finding of strong delocalization of the highest occupied molecular orbitals of GC by theoretical simulation and by modelling based on the Büttiker theory of partial coherent charge transport.

Original languageEnglish (US)
Pages (from-to)221-226
Number of pages6
JournalNature Chemistry
Volume7
Issue number3
DOIs
StatePublished - Mar 2015

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

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    Xiang, L., Palma, J. L., Bruot, C., Mujica, V., Ratner, M. A., & Tao, N. (2015). Intermediate tunnelling-hopping regime in DNA charge transport. Nature Chemistry, 7(3), 221-226. https://doi.org/10.1038/nchem.2183