Carbon Nanotubes and Graphene - Research and Applications

Researchers report the development of a novel nanoelectronic platform based on single wall carbon nanotube nanoelectrodes for directly probing the dc conductivity in DNA at the single-molecule level. Potential application of this study would be the identification of specific genes. Stretching and positioning of DNA molecules to the nanotube electrodes was achieved by using dielectrophoresis (DEP). E-beam lithography was used to make electrical contacts to the individual single wall carbon nanotubes. Researchers measured current values of 25-40 pA when a double-stranded DNA molecule bridged the nanotube electrode. In comparison, a single-stranded DNA molecule carried much lower current (1 pA or less). The application of a back-gate voltage showed that the bridging DNA molecule forms a p-type semiconducting channel between the single wall nanotube electrodes. This research demonstrated that nanotubes can efficiently be employed as nanoelectrodes for probing charge transport in DNA.