Single-walled carbon nanotubes (SWNTs) have been shown to display incredible optical and electrical characteristics. For example, metallic SWNTs, multi-walled nanotubes (MWNTs) and bundled SWNTs can withstand current densities up to 2 to 3 orders of magnitude higher than copper currently used in electronic chips. Semiconducting SWNTs that are isolated from each other display fluorescence in the near-infrared upon photoexcitation. This dissertation focuses on using the conductive nature and optical activity of NTs to construct hybrid nanotube-nanoparticle (NT-NP) devices and to create better stabilized aqueous SWNT suspensions, respectively.

Hybrid NT-NP devices were created by cutting NTs that connected two macroscopic gold electrodes using either high voltage pulses or an oxidative etch. Carboxylic acid groups present at the ends of the NT electrodes formed an amide bond with CdSe quantum dots that are stabilized with amine-terminated surface ligands. Alternatively, the acid groups were also converted to thiol groups and Au NPs were docked between the nanoelectrodes. Dielectrophoresis was used to guide Au NPs into the nanogap. In this way, NTs were used as nanoscale electrodes to connect nanoscale particles.

Sodium lauroyl sarconsinate (Sarkosyl) was used to create aqueous isolated SWNT suspensions, which were made more stable by cross-linking the Sarkosyl surfactant molecules wrapped around the SWNTs. 2,2'-(ethylenedioxy)bis(ethylamine) was used to link the Sarkosyl molecules together to form micellar cages around the SWNTs. Significantly, upon cross-linking the Sarkosyl surfactant, SWNTs remained largely isolated from one another even when the suspension was dried into densely packed nanotube films.

This work represents a step towards the manipulation of single particles to form multi-system functional devices and the creation of SWNT solutions that are fluorescent in solution and solid films. NT-NP devices show great promise for such applications as alternative energy photovoltaic systems and LEDs. The cross-linked Sarkosyl SWNT suspensions show potential for infrared biological fluorescence imaging applications. Further SWNT fluorescence studies are suggested to investigate why the bulk solution fluorescence quantum yield of SWNTs is low.