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Towards the Development of Phospholipid-Encapsulated Gold Nanorod Chains for Enhanced Raman-Scattering and the Improvement of Student Scientific Communication Skills in Undergraduate Classroom and Laboratory Setting

Posted on:2017-07-24Degree:Ph.DType:Thesis
University:University of Toronto (Canada)Candidate:Stewart, Alexander FFull Text:PDF
GTID:2461390011991005Subject:Nanoscience
Abstract/Summary:
Depending on functionalization, nanospecies can serve effectively as Surface Enhanced Raman Scattering (SERS) probes. Their efficacy can be improved by tuning their shape and concentrating their electric field profile into smaller regions. This tuning is seen particularly well in nanorods, which concentrate such fields near the rod tips or ends, in 'hotspots'. These hotspots can be constructively enhanced through the self-assembly of the nanospecies in question, further increasing the enhancement of Raman-active species within. When considering their potential application as SERS probes, both the separation of end-to-end assembled nanorods (gap size), as well as the degree of assembly (chain length), are factors that must be optimized to obtain maximal signal.;This thesis reports on the development of robust and variable methods for assembling gold nanorod species in an end-to-end configuration, and for investigating their effectiveness as SERS probes. Using both polymers and short charged ligands with control over their locations of attachment to gold nanorods, nanorod assembly could be initiated in a longitudinal direction either through changing the solvent system or through the introduction of bridging ligands. Exploitation of the inter-rod gap 'hotspot' region allowed for significant Raman enhancement of species located in said gap. Using phospholipids to encapsulate the assembling nanorod allowed for significant control over the proportions of species, in terms of length of the nanorod chain. This control allowed for further optimization of the Raman signals from species of interest.;This thesis also details the investigation, over a period of several academic years, of the success of the Writing Instruction and Training (WIT) program, an initiative to iteratively improve student written communication skills as they related to scientific chemical communication. In courses ranging from first to third year, undergraduates were provided with opportunities to explore their perceptions of scientific communication and receive extensive and formative feedback on all aspects of their submitted work, with an eye towards fostering improvement. Examining the impact both qualitatively and quantitatively revealed that such a program was highly successful in gradually building upon and expanding student knowledge of the traditions, styles, concepts and progressions of ideas so central to chemical communication.
Keywords/Search Tags:Communication, Enhanced, Student, Raman, Nanorod, SERS, Species, Gold
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