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dc.contributor.advisor Chilkoti, Ashutosh en_US
dc.contributor.author Nusz, Gregory en_US
dc.date.accessioned 2010-05-10T19:53:01Z
dc.date.available 2011-07-26T04:30:04Z
dc.date.issued 2010 en_US
dc.identifier.uri http://hdl.handle.net/10161/2264
dc.description Dissertation en_US
dc.description.abstract <p>The refractive index sensitivity of plasmonic nanoparticles is utilized in the development of real-time, label-free biodetection. Analyte molecules that bind to receptor-conjugated nanoparticles cause an increase in local refractive index that in turn induces an energy shift in the optical resonance of the particle. Biomolecular binding is quantified by quantitatively measuring these resonance shifts. This work describes the application and optimization of a biomolecular detection system based on gold nanorods as an optical transducer.</p> <p>A microspectroscopy system was developed to collect scattering spectra of single nanoparticles, and measure shifts of the spectra as a function of biomolecular binding. The measurement uncertainty of LSPR peak shifts of the system was demonstrated to be 0.3 nm. An analytical model was also developed that provides the optimal gold nanorod geometry for detection with specified receptor-analyte pair. The model was applied to the model biotin-streptavidin system, which resulted in sensing system with a detection limit of 130 pM - an improvement by four orders of magnitude over any other single-particle biodetection previously presented in the literature.</p> <p>Alternative optical detection schemes were also investigated that could facilitate mulitplexed biosensing. A theoretical model was built to investigate the efficacy of using a multi-channel detector analogous to a conventional RGB camera. The results of the model indicated that even in the best case, the detection capabilities of such a system did not provide advantages over the microspectroscopic approach.</p> <p>We presented a novel hyperspectral detection scheme we term Dual-Order Spectral Imaging (DOSI) which is capable of simultaneously measuring spectra of up to 160 individual regions within a microscope's field of view. This technique was applied to measuring shifts of individual nanoparticles and was found to have a peak measurement uncertainty of 1.29 nm, at a measurement rate of 2-5 Hz.</p> en_US
dc.format.extent 14436509 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject Engineering, Biomedical en_US
dc.subject Physics, Optics en_US
dc.subject Biodetection en_US
dc.subject Biosensor en_US
dc.subject Label-free en_US
dc.subject Nanoparticle en_US
dc.subject Plasmon en_US
dc.title Label-free Biodetection with Individual Plasmonic Nanoparticles en_US
dc.type Dissertation en_US
dc.department Biomedical Engineering en_US
duke.embargo.months 12 en_US

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