1. Department of Chemistry, Center of Biotechnology and Drug Design, Georgia State University, 33 Gilmer Street SE Unit 8, Atlanta, Georgia 30303, Integrated Microscopy and Microanalytical Facility, Emory University, 1515 Pierce Drive, Atlanta, Georgia 30322, Veterans Administration Medical Center, School of Medicine, Emory University, 1670 Clairmont Road, Decatur, Georgia 30033, and NanoSystems, 3000 Horizon Drive, King of Prussia, Pennsylvania 19406