1. Department of Chemistry, Department of Materials Science and Engineering, Department of Biomedical Engineering, Department of Pharmacology, International Institute for Nanotechnology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
2. Department of Biology, Evolution and Optics of Nanostructures Group, University of Ghent, Ledeganckstraat 35, Ghent 9000, Belgium
3. Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States