High-yield DNA-templated assembly of surfactant-wrapped carbon nanotubes

We have developed a straightforward approach for constructing single-walled carbon nanotube (SWNT) assemblies by using aligned surface DNA as a positioning template. A cationic surfactant, dodecyltrimethylammonium bromide, is utilized to suspend SWNTs in aqueous media and localize them on DNA through electrostatic interactions. SWNT positioning is controlled by the surface DNA arrangement, and the extent of deposition is influenced by the SWNT concentration. With lower-concentration SWNT suspensions, multiple surface treatments can increase the DNA coverage. Under optimized conditions, 83% of the length of surface DNAs was covered with SWNTs, and 76% of all surface-deposited SWNTs were on the DNA. In some regions, nearly continuous SWNT assemblies were formed. This approach should provide a useful tool for the fabrication of nanotube nanowires in nanoelectronic circuits.