A strategy to ameliorate non-specific adsorption of oligonucleotides onto Quantum Dots (QDs) is investigated where QDs are being used as a platform for the development of optical bioprobes for nucleic acid detection. Certain zwitterionic structures as coatings on QDs have recently been shown to reduce non-specific binding of proteins. In this thesis, a lysine side chain is attached to a dihydrolipoic acid (DHLA) derivative to create a zwitterionic bidentate ligand that has primary amine and carboxyl termini. Such coatings on CdSe/ZnS QDs were studied to assess adsorption of oligonucleotides across a range of pH to better understand the relationship between surface charge and adsorption. The change of pKa of charged terminal groups on QD surfaces for a variety of different water soluble ligands were evaluated using pseudo-titration curves, and indicated up to 3 orders of magnitude shift of pKa at a QD surface in comparison to pKa in bulk solution.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/32604 |
| Date | 02 August 2012 |
| Creators | Mahmud, Tasmea |
| Contributors | Krull, Ulrich Jorg |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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