| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Monday Sessions |
| Session NS-MoA |
| Session: | Nanomaterials in the Environment |
| Presenter: | K. Louis, University of Wisconsin-Madison |
| Authors: | K. Louis, University of Wisconsin-Madison O. Bar-Ilan, University of Wisconsin-Madison W. Heideman, University of Wisconsin-Madison M. Konrath, University of Wisconsin-Madison J. Pedersen, University of Wisconsin-Madison R. Peterson, University of Wisconsin-Madison S. Yang, University of Wisconsin-Madison R.J. Hamers, University of Wisconsin-Madison |
| Correspondent: | Click to Email |
Nanoparticles made from TiO2 and other metal oxides are of increasing interest for applications including sunscreens, cosmetics, paints, biomedical imaging, and photovoltaic devices. While TiO2 is generally considered to be non-toxic, TiO2 and other metal oxides can generate highly toxic reactive oxygen species when exposed to water and sunlight. The ROS species can, in turn, modify the stability of the TiO2 nanoparticles by altering the organic ligands that typically are present on the exterior of the nanoparticles. We are investigating the formation of ROS species by TiO2 nanoparticles and the relationship between organic ligands, ROS generation, and nanoparticle stability. These factors all affect the bioavailability of TiO2 nanoparticles and consequently are important factors in understanding the safety and health impacts of nanomaterials. As model systems, we have investigated TiO2 nanoparticles functionalized with several ligands including citrate, 3,4-dihydroxybenzaldehyde, and rutin, a model of humic substances. Using fluorescent probes we are measuring the amount of ROS species produced from nanoparticles of different sizes and relating this to the chemical alteration/degradation of the ligands using XPS and FTIR, and examining the impact on stability of nanoparticles in aqueous media. Concurrent measurements are being made of the toxicity of the nanoparticles using zebrafish in the presence and absence of ultraviolet light in order to understand how surface chemistry of nanoparticles ultimately impacts bioavailability and environmental impact of engineered nanomaterials.