Research interests: Chemistry of inorganic colloidal nanoparticles; microbial toxicology; microbe-mineral interactions

Brief Resesearch Description: The increasing use of nanotechnology in consumer products makes it inevitable that nanomaterials will be released into the environment. However, the environmental impacts of nanomaterials are still largely unknown. Studying the chemical behavior and biological effects of nanomaterials in environmental settings is key to understanding these impacts.

To this end, we are studying the effects of quantum dots (semiconductor nanoparticles of CdSe and CdS ) upon a common environmental bacterial species, namely Pseudomonas aeruginosa. In parallel with this study, we are also observing how bacteria affect the chemical and physical state of the quantum dots, examining aggregation state, dissolution and oxidation behaviors.

We have also focused our research efforts upon the size-dependent dissolution behavior of nanoparticulate lead sulfide (galena, PbS), a material of both natural and industrial relevance. In addition to examining the effects of nanoparticle size upon dissolution, we have also examined the effects of aggregation, as many natural nanomaterials are aggregated. We hope to extend these studies to other metal sulfides.