Download the full-sized PDF
Permanent link (DOI): https://doi.org/10.7939/R38P5VM6F
This file is in the following communities:
|Graduate Studies and Research, Faculty of|
This file is in the following collections:
|Theses and Dissertations|
Modification and Application of Gold Nanoparticles in Surface-Based Immunoassays Open Access
- Other title
- Type of item
- Degree grantor
University of Alberta
- Author or creator
Laurentius, Lars B
- Supervisor and department
McDermott, Mark (Chemistry)
- Examining committee member and department
Serpe, Michael (Chemistry)
Gibbs-Davis, Julianne (Chemistry)
Zhong, Chuan-Jian (Chemistry, State University of New York)
Evoy, Stephane (Electrical and Computer Engineering)
McCreery, Richard (Chemistry)
Department of Chemistry
- Date accepted
- Graduation date
Doctor of Philosophy
- Degree level
Gold nanoparticles (AuNPs) are at the forefront of many research areas and generally require very specific surface functionalities to be compatible with targeted applications. Suitable modification schemes should be simple, fast, and robust. A common surface modification involves the use of thiols to coat the AuNPs with a thiolate monolayer; however, the lability of the sulfur-gold interaction can create problems in applications where high stability is required. Alternatively, this thesis explored the use of diazonium salts to modify gold nanoparticles.
In recent years diazonium cation grafting onto planar substrates has gained significant attention. The resulting layers show resilience and controllable properties such as film thickness and functionality. In order to extend this surface chemistry to include AuNPs, the conditions necessary for the spontaneous chemisorption of diazonium derived aryl films to pre-formed gold nanoparticles were developed. The spectroscopic characterization of these organic layers on gold nanoparticles provided evidence for a gold-carbon covalent bond. A direct comparison of nitrobenzene diazonium salt derived layers to the thiol analogue was used to show that diazonium salt modification schemes are similarly simple and fast in comparison, but also exhibit marked differences in film structure as they produce multilayers.
Gold nanoparticles are widely used in biosensing applications providing unique optical properties for signal enhancement and detection schemes. In UV-vis spectroscopy, localized surface plasmon resonance (LSPR) of the AuNPs
leads to an absorption band. The work presented in this thesis explored the capability of utilizing the LSPR band magnitude in a simple transmission UV-vis measurement to determine the nanoparticle density of adsorbed NPs on a transparent substrate. This led to the development of a new method to incorporate AuNPs as extrinsic labels in a sandwich immunoassay. The analyte, rabbit IgG, is captured on a transparent surface and labeled with AuNPs. This was accomplished by tailoring the surface chemistry of the nanoparticles specifically to the target analyte. Consequently, quantitating the magnitude of the LSPR band determines the number of AuNP-labels present on the biochip surface, which in turn is proportional to the analyte concentration captured. In this fashion detection limits on the order of 100 pM were achieved.
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
- Citation for previous publication
Laurentius, L.; Stoyanov, S. R.; Gusarov, S.; Kovalenko, A.; Du, R.; Lopinski, G. P.; McDermott, M. T. ACS Nano 2011, 5, (5), 4219-4227.
- Date Uploaded
- Date Modified
- Audit Status
- Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 16033930
Last modified: 2015:10:12 19:07:34-06:00
Filename: Laurentius_Lars_Fall 2012.pdf
Original checksum: 18a27a60d72a5b2d15fd67b66dbc2a21
Well formed: true
Status message: File header gives version as 1.4, but catalog dictionary gives version as 1.3
Status message: Too many fonts to report; some fonts omitted. Total fonts = 1506
File title: Microsoft Word - Laurentius_Lars_Fall 2012.docx
File author: Lars Laurentius
Page count: 193