Electrically triggered insertion of single-stranded DNA into single-walled carbon nanotubes

The formation of DNA encapsulated carbon nanotubes, which are expected to modify electronic properties of carbon nanotubes, is for the first time demonstrated using a modified electrophoresis method. Radio-frequency and direct-current electric fields are applied to the DNA solution in order to stretch random-coil-shaped DNA and irradiate DNA to carbon nanotubes that are coated onto electrodes immersed in the DNA solution, respectively. Transmission electron microscopy and Raman scattering spectroscopy analyses reveal that DNA can be encapsulated into the carbon nanotubes. In this procedure, the key for the formation of DNA encapsulated carbon nanotubes is found to irradiate the stretched-shaped DNA to the carbon nanotubes.