Thesis Format
Monograph
Degree
Master of Science
Program
Chemistry
Supervisor
Hedberg, Yolanda
Abstract
Gold nanoparticles (AuNPs) have become promising candidates for various biomedical applications due to their unique physicochemical properties and biocompatibility. Nevertheless, the efficacy of AuNPs in these applications highly relies on their stability and ability to maintain their desired properties within the complex environment of the human body. This thesis investigates the stability and aggregation behavior of citrate-coated AuNPs in in-vitro physiological environments and nitrogen heterocyclic carbene (NHC)-coated gold nanoclusters (AuNCs) in water over time. Analytical techniques such as electrophoretic mobility, dynamic light scattering, and inductively coupled plasma mass spectrometry were employed. It was shown that cell media (in contrast to phosphate buffered saline) enhanced AuNP stability via protein corona formation, while AuNCs maintained consistent stability over one month in water. The size and concentration of AuNPs influenced their aggregation behavior, with smaller particles and higher concentrations, increasing the aggregation tendency. Overall, this thesis contributes to the development of biomedical nanomaterials.
Summary for Lay Audience
Gold nanoparticles (AuNPs) are engineered, extremely small pieces of gold, typically ranging between 1 and 100 nm in size. Due to their small size, they have unique properties that distinguish them from bulk or other forms of gold, that make them highly valuable across a range of scientific and biomedical applications. For instance, they are generally considered biocompatible, meaning they are well-tolerated by living organisms and are unlikely to cause harm when properly synthesized and used. These characteristics make them a good candidate for biomedical applications with the potential to address various medical challenges. In this case, one of the most important properties of AuNPs is to show good chemical stability in a biological environment, since this would change their long-term functionality. In this thesis, Chapter 1 provides a comprehensive explanation of the properties of AuNPs and their impact on stability behavior. The stability of citrate-coated AuNPs in a biological environment is investigated using a range of analytical techniques to assess their size, concentration, and behavior under various conditions and over time. These methods are thoroughly described in Chapter 2 of this thesis. The results of these investigations demonstrated that protein interactions in biological environments help stabilize AuNPs by forming a corona layer around the particles, preventing aggregation, and preserving their size and properties. A detailed discussion of these findings is provided in Chapter 3 of this thesis. Chapter 4 focuses on the stability of NHC-coated gold nanoclusters (AuNCs) in water over time. AuNCs are one type of AuNPs, consisting of a small number of gold atoms that form clusters ranging in size from 1 to 3 nm. At the end, Chapter 5 offers a comprehensive conclusion to the study, along with insights into future research directions.
Recommended Citation
Hajighasemi, Narges, "Investigating the Stability of Different Sizes of Gold Nanoparticles in Physiological Environments and Different Gold Nanoclusters in Water." (2024). Electronic Thesis and Dissertation Repository. 10399.
https://ir.lib.uwo.ca/etd/10399