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dc.contributor.advisor Halas, Naomi J.
dc.creatorBarhoumi, Aoune
dc.date.accessioned 2013-03-08T00:32:53Z
dc.date.available 2013-03-08T00:32:53Z
dc.date.issued 2012
dc.identifier.urihttp://hdl.handle.net/1911/70208
dc.description.abstract Gold nanoshells are tunable plasmonic nanostructures consisting of spherical silica cores wrapped with thin layer of Au. Based on the size of the Au layer with respect to the silica core, gold nanoshells can resonantly absorb or scatter light at any wavelength on the visible or infrared. On resonance, gold nanoshells interact strongly with light to give rise to collective oscillations of the free electrons against the background of the ionic core, phenomena known as localized surface plasmons. The free electron oscillation creates surface plasmon multimodes of various orders. As a result, the average local near field surrounding the Au nanoshell is enhanced. The local field enhancement has been extensively used in different applications. In this work, the local near-field is used to enhance the Raman spectroscopy of DNA and explore the different modes attributed to the base composition and structure of the DNA sequence. We showed that urface enhanced Raman spectroscopy of DNA is dominated by the adenine modes regardless of the base composition of the DNA sequence, a property that we have used to develop a DNA label-free detection system. As absorbers, plasmon-resonant Au nanoshells can convert absorbed light into heat. As a consequence, the temperature on the Au nanoshell surface increases dramatically. This property is used to light-trigger the release of variety of therapeutic molecules such as single stranded DNA, siRNA and small molecules. We demonstrated that the local heat can be used to dehybridize double stranded DNA attached to the Au surface via a thiol moiety on one of the DNA strands. The complementary sequence (therapeutic sequence) is released at temperature lower than the standard melting temperature of same DNA sequence. Moreover, small molecules (DAPI) which were initially intercalated on the double stranded DNA attached to the Au surface were successfully released due to the heat generated around the nanoshell surface. Finally, siRNA molecules were also released using a different system made of PLL (polylysine) attached to Au nanoshells. The electrostatic interaction between the negatively charged siRNA and the positively charged PLL was overcome by the thermal perturbation causing the siRNA to be released. In vitro experiments successfully showed the release of siRNA, single stranded DNA and small molecules.
dc.format.extent 138 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectHealth sciences
Environmental science
Applied sciences
Pure sciences
Gold nanoshells
Drug delivery
Drug release
DNA detection
Plasmonics
Physical chemistry
Pharmacy sciences
Nanotechnology
dc.title Gold nanoshells for surface enhanced Raman spectroscopy and drug delivery
dc.identifier.digital BarhoumiA
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Chemistry
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation Barhoumi, Aoune. "Gold nanoshells for surface enhanced Raman spectroscopy and drug delivery." (2012) PhD diss., Rice University. http://hdl.handle.net/1911/70208.


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