Biomolecule-directed assembly of self-supported, nanoporous, conductive, and luminescent single-walled carbon nanotube scaffolds.

A single-walled carbon nanotube self-suspended network of exceptionally low density is formed by DNA-streptavidin-assisted assembly where the DNA complex serves as a cross-shaped point connector. The macroscopic nanotube aerogel is conductive and luminescent and presents an excellent scaffold for subsequent functionalization. For example, platinum and titanium dioxide coating of the nanotube network is demonstrated.

Optical properties of assembled single-walled carbon nanotube gels.

A macroscopic system of single-walled carbon nanotubes (SWNTs) created by a novel DNA/protein complex-assisted assembly is investigated. Due to a point-like nature of connectors, the resulting SWNT aerogel represents a network of self-suspended nanotubes with a record-low density of less than 0.75 mg cm(-3).

Noncovalent functionalization of DNA-wrapped single-walled carbon nanotubes with platinum-based DNA cross-linkers.

A method for noncovalent functionalization of DNA-wrapped single-walled carbon nanotubes (SWNTs) using platinum-based DNA cross-linkers is investigated. In particular, cisplatin and potassium tetrachloroplatinate are shown to bind to DNA that encapsulates SWNTs in aqueous solution. The bound platinum salt can then be reduced to decorate the DNA-encapsulated SWNTs with platinum nanoparticles.

Optical signatures of the Aharonov-Bohm phase in single-walled carbon nanotubes.

We report interband magneto-optical spectra for single-walled carbon nanotubes in high magnetic fields up to 45 tesla, confirming theoretical predictions that the band structure of a single-walled carbon nanotube is dependent on the magnetic flux phi threading the tube. We have observed field-induced optical anisotropy as well as red shifts and splittings of absorption and photoluminescence peaks. The amounts of shifts and splittings depend on the value of phi/phi(0) and are quantitatively consistent with theories based on the Aharonov-Bohm effect.