Research Colloquium: Patricia Holden

The Bren School of Environmental Science & Management
at the University of California, Santa Barbara



Patricia Holden
Bren School of
Environmental Science & Management

Thursday, Oct. 15, 2009
12:30 - 1:30 p.m.
Bren Hall 1414

"Interactions Between Pseudomonas aeruginosa and CdSe Quantum Dots"

Hosted by John Melack



Engineered nanomaterials are increasingly used in consumer products, and are promising solutions to environmental concerns, including energy supply. One category of engineered nanomaterials, quantum dots (QDs), are of particular interest in photovoltaics and for imaging in clinical medicine. QDs synthesized from cadmium and selenium, CdSe QDs, can be made to fluoresce brightly with emission spectra precisely related to their size. Given their metal and metalloid composition, questions arise regarding their fates and consequences in the environment. Do CdSe QDs break down? Are cadmium ions released? What is the fate of the selenide? How do environmental bacteria, which are present in every environmental compartment, affect potential fates and transport of CdSe QDs? This talk concerns a published study of one environmentally relevant bacterial strain that was exposed to either Cd(II), selenite, or CdSe QDs while growing. We learned about the relative effects of Cd(II) and selenite to growth, and the fates of CdSe QDs under biotic and abiotic conditions. Generalizable insights regard approaching the nascent field of environmental fates and effects of engineered nanomaterials, with a particular emphasis on metallic particles.


Patricia Holden is a professor of environmental microbiology at the Bren School. The Holden lab researches microbiological water quality, vadose-zone microbial ecology, unsaturated biofims, microbial community ecology in water and soils, and bacterial interactions with engineered nanomaterials to understand mechanisms of interactions as well as fates of nanomaterials in soils.


NOTE: Research colloquia are hosted by Bren faculty members and are generally high-level talks about research in a particular area of environmental science and management.



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