1. Environmental Science and Engineering Doctoral Program, The University of Texas at El Paso, 500 W University Avenue, El Paso, Texas 79968, United States
2. University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 W University Avenue, El Paso, Texas 79968, United States
3. MSU DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
4. Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 W University Avenue, El Paso, Texas 79968, United States