rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Whispering-gallery modes in quantum dot embedded microspheres for sensing applications
  name:
    name part: Beier, Hope T.
    role:
      role term: creator
  name:
    name part: Meissner, Kenith E.
    role:
      role term: thesis advisor.
  name:
    name part: Cote, Gerard L.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2011
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: New methods of biological analyte sensing are needed for development of miniature biosensors that are highly sensitive and require minimal sample preparation. One novel technique employs optical resonances known as Whispering Gallery Modes (WGMs). These modes arise from total internal reflection of light at the internal surface of a high index microsphere within a low index medium and produce an evanescent field that extends into the surrounding medium. The WGMs produce multiple narrow spectral peaks that shift position with variations in the local index of refraction sampled by the evanescent tail of the WGMs. To excite these WGMs, we embed quantum dots (QDs) in the periphery of polystyrene microspheres to serve as local light sources. By coupling emission from the QDs to the WGMs, the sensors can be excited and interrogated remotely and, by monitoring the shift of multiple resonance modes, may provide higher sensitivity and accuracy compared with similar techniques. The high refractometric sensitivity of the WGMs offers potential for trace detection of molecules adsorbed onto or bound to the microsphere sensor elements. The sensitivity of these sensors is demonstrated by monitoring the wavelength shift of multiple resonant modes as bulk index of refraction is changed. The potential for targeted biosensing is explored through addition of a protein that adsorbs to the microsphere surface, thrombin. Microsensor response in all cases demonstrated increased sensitivity over theoretical predictions. Models based on Mie theory and continuity of the radial functions across the sphere-media interface were used to model the location, Q-factor, and sensitivity of the WGMs in microspheres by considering the embedded QDs as a high index outer layer. This model was used, along with estimates of the QD-layer index and penetration depth, to relate the locations and sensitivities of the modes to our experimental results with strong agreement between the two. In all, these microsph…
  note: by Hope T. Beier.
  note: "Major Subject: Biomedical Engineering"
  note: Title from author supplied metadata (automated record created 2011-02-28 11:02:00).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2009 http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7507
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major biomedical engineering
  subject:
    topic: Biosensing
  subject:
    topic: Quantum Dots
  subject:
    topic: Microspheres
  subject:
    topic: Scattering Theory
  subject:
    topic: Whispering Gallery Modes
  subject:
    topic: Refractive Index
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7507
  record info:
    record content source: TXA
    record creation date: 110310
    record change date: 20151202115720.0
    record identifier: in00002642087