THE BIOLOGICAL AND ENVIRONMENTAL IMPLICATIONS OF Ag AND TiO2 NANOPARTICLES

The fate and transport of metal and metal oxide nanoparticles within environmental and biological systems is currently an area of focus within the scientific community due to both their unusual behavior relative to bulk materials and their entry into different ecosystems through use in various customer products. The study of their interactions with biologically and environmentally common organic molecules is of special interest as these are widely found in environmental systems as natural organic matter. This research explores the aggregation and sedimentation of TiO2 and Ag nanoparticles within aqueous environments at a range of pH, ionic strengths, and particle concentrations resembling natural environments as a function of surface amino acid adsorption. Analysis was performed using UV-Vis spectroscopy, dynamic light scattering and measurement of particle zeta potential. Although the primary objective of this research lies in studying the fate and transport of Ag and TiO2 nanoparticles when presented with amino acids such as cysteine, the formation of a charge-transfer complex between Ag nanoparticles and L-cysteine was observed and some insight was gained as to the complex structure, formation, and potential effects on the fate and transport of Ag NPs.