1. Department of Chemistry; Center for optical materials science and engineering (COMSET) and environmental toxicology program; Clemson University; Clemson SC 29634 USA
2. Department of Materials Science Engineering; Center for optical materials science and engineering (COMSET); Clemson University; Clemson SC 29634 USA
3. Department of Bioengineering; 301 Rhodes Research Center; Clemson SC 29634 USA
4. Vanderbilt University Medical Center, AAA 3107 MCN; Nashville TN 37232 USA