Use this URL to cite or link to this record in EThOS:
Title: Electrochemical deposition of polymeric nanostructures and their biosensing applications
Author: Choong, C. L.
Awarding Body: University of Cambridge
Current Institution: University of Cambridge
Date of Award: 2011
Availability of Full Text:
Full text unavailable from EThOS.
Please contact the current institution’s library for further details.
Free-standing carbon nanotube or fiber (CNT/CNF) arrays were employed to template the growth of molecular (caffeine) imprinting polymer. The vertically aligned CNT/CNFs were deposited by plasma enhanced chemical vapour deposition (PECVD) onto different metallic buffer layers on silicon substrates. In the selection of the metallic buffer layer, titanium outperformed other metals in term of its electrical conductivity, adhesion and CNT yield. Direct deposition of sparse CNT arrays, with approximately half a micron tube-to-tube spacing, and dense CNT forests were developed. When these new CNT-polymer architectures were employed in amperometic sensing of caffeine molecules, an increase in sensitivity with the packing density of CNT was observed. In templateless synthesis, the shape-controlled growth mechanism of polymer nanocrystals was studied using chitosan biopolymer. It was found that the 10 to 20 nm sized nanoparticles in the growth solution were the basic building blocks in the formation of the nanocrystals. In general, a large number of nanoparticles which are free from chain entanglement produced a high yield of nanocrystals. The shape of the chitosan nanocrystals could be controlled through the nanoparticle concentration and the applied potential. For biosensing applications, the electrically stimulated actuation of conducting polymers (CP) was first explored in developing a new concept of smart sensing. The smart sensing was achieved by modulating the detection window of a CP based biosensor to accommodate the measuring range of a specific test solution. This new concept was experimentally investigated using a submicron thick biocompatible CP, polypyrrole, with molecular (caffeine) imprinting for caffeine detection. The modulation of the detection window was observed by varying the application pulsed potential of these biosensors.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available