On the Kinetic Elucidation of the Synthetic Mechanisms of Silver Nanoparticles (AgNPs) for Application in Localized Surface Plasmon Resonance (LSPR) Based Enhancement of Triplet State Quantum Yields

The use of plasmonic silver nanoparticles (AgNPs) in relation to catalysis, medicine, and new emerging solid-state technologies has been widely explored in the past two decades and is a culmination of a century of discovery and application. However, the replicability of AgNPs syntheses is inconsistent. It is reagent batch dependent at best and irreproducible at worst. This thesis explores a streamlined method of synthesizing AgNPs by adapting the Tollen’s reagent at optimized concentrations to obtain a facile, robust, and reproducible, room-temperature seed-mediated synthesis with a high degree of size control. The role of solvent mixtures in this novel synthesis was investigated with a conclusion that acetonitrile plays a role in inhibiting nucleation when compared to pure water. Though the role is not fully elucidated, the acetonitrile may allow for more uniform nanoparticle growth at higher concentrations of seeds as the kinetics of seed growth do not seem to change as the concentration of seeds increases. This optimized method of AgNPs synthesis was then tested with current functionalization protocols that include but are not limited to silica coating, amination, and conjugation of xanthene dyes. This was done to explore potential enhancements of photophysical processes, specifically with respect to the enhancement of singlet oxygen production. This part of the thesis is inconclusive. However, an optimization in the testing of dye conjugation is proposed with potential time savings for future work.