Tunnel conductance of Watson-Crick nucleoside-base pairs from telegraph noise

Shuai Chang, Jin He, Lisha Lin, Peiming Zhang, Feng Liang, Michael Young, Shuo Huang, Stuart Lindsay

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


The use of tunneling signals to sequence DNA is presently hampered by the small tunnel conductance of a junction spanning an entire DNA molecule. The design of a readout system that uses a shorter tunneling path requires knowledge of the absolute conductance across base pairs. We have exploited the stochastic switching of hydrogen-bonded DNA base-nucleoside pairs trapped in a tunnel junction to determine the conductance of individual molecular pairs. This conductance is found to be sensitive to the geometry of the junction, but a subset of the data appears to come from unstrained molecular pairs. The conductances determined from these pairs are within a factor of two of the predictions of density functional calculations. The experimental data reproduces the counterintuitive theoretical prediction that guanine-deoxycytidine pairs (3 H-bonds) have a smaller conductance than adenine-thymine pairs (2 H-bonds). A bimodal distribution of switching lifetimes shows that both H-bonds and molecule-metal contacts break.

Original languageEnglish (US)
Article number185102
Issue number18
StatePublished - 2009

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Tunnel conductance of Watson-Crick nucleoside-base pairs from telegraph noise'. Together they form a unique fingerprint.

Cite this