Opto-acoustic characterization of chitosan based gold nanoparticles (GNPs) synthesized in the presence of monovalent salt

Several studies, over recent years, focus on the use of chitosan, a biocompatible macromolecule, to form gold nanoparticles (GNPs). In this study, gold nanoparticles were synthesized using chitosan and Chloroauric acid, under stirring which cause micro/nano-gels to form. Ultraviolet (UV) light is used to reduce solution into gold nanoparticles, in which the resulting nanoparticles are biocompatible after this reduction. In effort to obtain nanoparticles of different shape and size using the chitosan, different concentrations of monovalent salt, were added to the chitosan solution. The different signatures of the particles based on the concentration of the salt in the solution are observed using an optoacoustic setup to detect morphological changes in the particles due to shifts in the absorption resonance. The optoacoustic measurements are compared to the absorption spectra of the gold nanoparticles. The overall goal of this study is to investigate the influence of chitosan, with the addition of the monovalent salt, on the formation of the biocompatible gold nanoparticles. This characterization will aid in the preparation of measurements to take on these particles in other portions of the electromagnetic spectrum such as radio frequencies.