1. Department of Chemical and Biomolecular Engineering, University of California─Berkeley, Berkeley, California 94720, United States
2. Department of Chemistry, University of California─Berkeley, Berkeley, California 94720, United States
3. School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
4. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States