Polarisation Techniques for Surface Plasmon Resonance Sensors

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dc.contributor.advisor Watkins, L en
dc.contributor.advisor Leonhardt, R en
dc.contributor.author Graham, David en
dc.date.accessioned 2011-01-26T03:39:58Z en
dc.date.issued 2011 en
dc.identifier.uri http://hdl.handle.net/2292/6135 en
dc.description.abstract Surface plasmons are electromagnetic waves that propagate along the interface between a metal and a dielectric. Surface plasmons can be excited by attenuated total internal reflection of p-polarised light at a thin metal layer separating a prism from a lower refractive index dielectric. The coupling to the plasmon is very sensitive to the refractive index of the dielectric and this is the basis of surface plasmon resonance (SPR) sensors. SPR sensors, using a metal surface coated with a sensitising layer to which an analyte of interest binds, have found significant applications in biosensing. The amplitude and phase of p-polarised light both change rapidly at the resonance so polarisation techniques can therefore be used to detect very small variations in the refractive index. This thesis presents two SPR instruments using polarisation techniques. A polarisation imaging SPR instrument is constructed. Linearly polarised light is reflected from an SPR surface, is incident on a polarisation analyser and the transmitted light detected with a camera. The input polarisation that gives minimum transmission through the optical system is measured for each pixel of a 128 × 48 pixel image. A theoretical analysis of the effect of various experimental conditions on the accuracy of refractive index measurements made with this instrument is presented. Measurements made with salt solutions are presented to demonstrate that refractive index changes can be detected over a 0.01 RIU range near n = 1.33. The noise in the refractive index is 2×10−6, similar to that expected from the theoretical analysis. A gold surface patterned with a fluoropolymer is used to demonstrate that spatially varying refractive index changes can be imaged. A novel technique for differential SPR measurements that detects the difference in refractive index between two areas of a SPR surface was developed. A theoretical analysis of this instrument shows that it should be able to detect changes in the difference of the refractive indices of the two areas. Measurements with salt solutions are presented to demonstrate that this instrument can detect refractive index differences while being insensitive to changes in the refractive index common to both areas of the SPR surface. en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof PhD Thesis - University of Auckland en
dc.relation.isreferencedby UoA99207898214002091 en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ en
dc.title Polarisation Techniques for Surface Plasmon Resonance Sensors en
dc.type Thesis en
thesis.degree.discipline Physics en
thesis.degree.grantor The University of Auckland en
thesis.degree.level Doctoral en
thesis.degree.name PhD en
dc.rights.holder Copyright: The author en
pubs.peer-review false en
pubs.elements-id 202110 en
pubs.record-created-at-source-date 2011-01-26 en

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http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc-sa/3.0/nz/


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