Contacting gold nanoparticles with carbon nanotubes by self-assembly

Single-wall carbon nanotubes (SWNTs) were functionalized with biotin at the ends and sidewalls of the nanotubes in a series of chemical reactions. Streptavidin-coated gold nanoparticles were attached to the biotin-modified SWNTs in solution in a self-assembly process. Gold nanoparticles which connected two SWNTs were selected and contacted for transport measurements. At low temperatures, Coulomb blockade oscillations were observed as a function of gate voltage. The size of the nanoparticles can be enlarged by catalytic deposition of gold leading to current increase through the SWNT–nanoparticle–SWNT junction.