1. Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
2. Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
4. Department of Physics, Northeastern University, Boston, Massachusetts 02115, United States
5. Department of Physics, University of California at Irvine, Irvine, California 92697, United States
6. Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States