Solution manipulation of single-walled carbon nanotubes and their applications in electrochemistry

Single-walled carbon nanotubes (SWNTs) are a unique family of all carbon one dimensional nanomaterials that offer extraordinary mechanical, electrical and thermal properties leading to great promises in applications ranging from composite materials, nanoelectronics, electrochemical devices, biology to analytical science. This dissertation describes the synthesis and solution manipulation of single-walled carbon nanotubes and their applications in electrochemistry.;Single-walled carbon nanotubes were synthesized by chemical vapor deposition method. SWNTs were individually and randomly grown on silicon substrates, which were used in study of the dielectric properties of SWNTs.;As-produced SWNT bundles were individually dispersed in aqueous solution using designed "polysoap" surfactants. The polysoaps are synthesized by functionalizing the side chain of poly(styrene-alt-maleic acid) with aminopyrene. The designed polysoaps adsorb on the sidewalls of SWNTs and exhibit dispersion efficiency better than DNA. In addition, SWNT-metal nanoparticle (NP) assemblies were synthesized by using the polymer-SWNT complexes as templates for the binding of metal ions and metal NPs.;Temperature and pH-responsive single-walled carbon nanotube dispersions were realized by using poly(N-isopropylacrylamide) and poly- L-lysine solutions as dispersion surfactants. The dispersion or aggregation of SWNTs in water can be controlled by adjust the temperature or pH values of the solution.;Transparent and conducting SWNT thin film were prepared and used as electrochemical electrodes for bioactive redox enzymes or photosystem II (PSII) immobilization. The employment of SWNT thin films as electrodes alleviates the requirement for metal or glassy carbon supporting electrodes and direct electron transfer is observed on laccase-SWNT cathodes. The amperometric response to the visible light of PS II--SWNT film bioelectrode reveals the potential application in PS II based solar cells.;Glucose oxidase (GOx) was immobilized on glassy carbon electrode using poly-L-lysine (PLL) and Nafion polymers. The Nafion-PLL-GOx modified electrodes display direct electron transfer (DET) without the aid of any nanomaterials. The GOx in modified electrodes retains its biocatalytic activity and oxidizes glucose efficiently.