1. Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
2. The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
3. The Institute for Biophysical Dynamics, Chicago, Illinois 60637, United States
4. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
5. Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138, United States
6. John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States