Mechanistic investigation of radiolysis-induced gold nanoparticle formation for radiation dose prediction

Nanoparticles have numerous uses in biomedical sciences, and this study addresses the mechanisms responsible for the formation of gold nanoparticles (GNPs) for measuring doses of ionizing radiation used in clinical radiotherapy. GNPs synthesized at various radiation doses were experimentally characterized and two mathematical models were developed to simulate the kinetics of the synthesis process. The first is similar to the Fink-Watzke model and predicts the rate of soluble gold salt conversion to GNPs, and the second model is based on a population balance model and predicts both nanoparticle concentration and size distribution. The model parameters that provided an optimal fit to experimentally gathered data were determined, and both models were able to capture the experimental absorbance time trends, which indicated the formation of gold nanoparticles. The population balance model, however, had the greater predictive power as it captured mean particle size trends that were consistent with experimental measurements.