Attachment of single CdSe nanocrystals to individual single-walled carbon nanotubes

Single amine functionalized CdSe quantum dots were coupled to individual acid-chloride modified single-walled carbon nanotubes via amide bond formation. The quantum dot-nanotube conjugates were characterized by atomic force and transmission electron microscopies. For single-walled nanotubes with lengths of < 200 nm, binding of quantum dots occurred at the nanotube ends, whereas longer nanotubes showed evidence of sidewall attachment. The number of bound quantum dots per nanotube can relatively be controlled by varying the quantum dot/nanotube mass ratio. These quantum dot-nanotube complexes have the potential to serve as a basis for future nanoelectronic devices.