Despite intensive efforts in the nanoelectronics community, the charge transport measurements in dsDNA provided a variety of results. This variability originated from the application of different experimental and environmental conditions, and from the different number of molecules measured in parallel. We have, therefore, developed in the last few years a method to measure 10 nm long single dsDNA molecules that are chemically connected to a gold substrate and a gold nanoparticle at their opposite ends, in a controlled way using special scanning probe microscopy methods. These measurements showed that relatively high currents can be transported through single dsDNA molecules. These high currents suggest that the charge transport mechanisms that govern the charge transfer in donor-bridge-acceptor systems in solution can not naively account for the high currents that we measure. Faster mechanisms should be called for. The results were reported in PNAS, Faraday discussions† and recently in Nanotechnology.


Further measurements using this method are expected to yield more accurate and reliable information on the charge transport mechanisms in dsDNA that are extremely difficult to obtain by alternative measurement methods.

This work was performed at the Hebrew University by Hezy Cohen, Daniela Ullien and Claude Nogues, under the supervision of Danny Porath, in collaboration with the group of Ron Naaman at the Weizmann Institute.

The work was supported by EU projects DNA NANOWIRES (IST-2001-38951) and DNA NANODEVICES (FP6-029192) and by the German Israel Foundation grant number I-892-190.10/2005.