In this work, the fabrication of noble metal nanostructures with interesting and useful optical properties was investigated. Nanoporous alumina templates were used as a basis for the production of gold nanowire and nanotube arrays, and the fabrication conditions can be changed to alter the array dimensions. The structures were characterised optically and the modes observed were described using finite element analysis; nanowires support a transverse and longitudinal resonance at non-zero angles, and nanotubes have a broad resonance at normal incidence. These resonances are highly sensitive to the dielectric environment surrounding their surface. Additionally, polymer nanodome arrays were created using a process of soft nanoimprint lithography, leading to the creation of uniform nanostructures over a large area. The domes were then coated in a thin film of gold or silver which allowed the domes to support localised surface plasmon resonances which were also found to be highly sensitive to the surrounding medium. Throughout this work, the potential for each nanostructure to be applied to plasmonic sensing was realised. The advantages of using arrays of nanowires and nanotubes is that, unlike label-based techniques which only confirm the presence or absence of a detector molecule, they are label-free methods which provide direct information on analyte binding to the target molecules via a change in the observed optical properties. The optical properties of the nanostructures produced in this work have been studied extensively and the effect of changing the dimensions of these are well understood. This means that the nanostructures used in this work show great potential for applications which involve sensing on the molecular level, particularly due to the tunability of their resonance peaks and the ability to produce the nanostructures uniformly over large areas.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:579740 |
| Date | January 2012 |
| Creators | McClatchey, Christina Lucia |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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