Doctor of Philosophy (PhD)
Biological and Chemical Sciences
Faculty of Science
The vast potential of nanoparticles and nanotechnology remains largely untapped; the crucial bottleneck being the knowledge gap between making and using nanoparticles (NPs). This PhD work bridges this gap by focusing on synthesizing nanoparticles with applications at the forefront. Four peer-reviewed publications are presented in Chapters 3-6, a safety and toxicological perspective is given in Chapter 7, and current work and future progress are summarized in Appendix 1. Bimorphic silver nanoparticles were prepared, presenting an innovative method to synthesize diverse nanostructures using polymeric surface blocking to break symmetry in seeded regrowth (Chapter 3).1 Silver stars with D5h symmetry were also synthetized using seeded regrowth and polymeric surface blocking (Chapter 4).2 Both were proven to be beneficial in sensing applications, specifically surface plasmon resonance and surface enhanced Raman spectroscopy. To mediate the chemical stability of silver, gold coating and templating was used, which was also proven beneficial for sensing applications (Chapter 5).3 Using gold as a protective coating has enabled the development of metallodielectrics with a silver decahedral core, gold coating, and metal oxide shells. The method included in this work prepares shells of MnO2-x, FeOOH, IrOx, and SiO2, with varying porosities and advantages for sensing (Chapter 6).4 Reflecting on the contributions of this work, these four accounts present rational design pathways that are transferable to different systems, enabling properties to be tailored for the desired application. This bridges the gap between potential and realized applications.
(1) Cathcart, N.; Kitaev, V. Symmetry Breaking by Surface Blocking: Synthesis of Bimorphic Silver Nanoparticles, Nanoscale Fishes and Apples. Sci. Rep. 2016, 6, 32561.
(2) Cathcart, N.; Coombs, N.; Gourevich, I.; Kitaev, V. Synthesis and Sensing Properties of D5h Pentagonal Silver Star Nanoparticles. Nanoscale 2016, 8, 18282–18290.
(3) Cathcart, N.; Chen, J. I. L.; Kitaev, V. LSPR Tuning from 470 to 800 nm and Improved Stability of Au–Ag Nanoparticles Formed by Gold Deposition and Rebuilding in the Presence of Poly(Styrenesulfonate). Langmuir 2018, 34, 612–621.
(4) Cathcart, N.; Murshid, N.; Campbell, P.; Kitaev, V. Selective Plasmonic Sensing and Highly Ordered Metallodielectrics via Encapsulation of Plasmonic Metal Nanoparticles with Metal Oxides. ACS Appl. Nano Mater. 2018, 1, 6514–6524.
Ritter, Nicole, "Nanoscale Building Blocks: Bridging the Gap between Potential and Realized Applications" (2019). Theses and Dissertations (Comprehensive). 2167.