1. Center for Biophysics and Computational Biology; University of Illinois at Urbana-Champaign; Urbana Illinois 61801 USA
2. Department of Chemical and Biomolecular Engineering; University of Illinois at Urbana-Champaign; Urbana Illinois 61801 USA
3. Department of Chemistry; Johns Hopkins University; Baltimore Maryland 21218 USA
4. Department of Chemical and Biomolecular Engineering, Center for Biophysics and Computational Biology, Department of Materials Science and Engineering; University of Illinois at Urbana-Champaign; Urbana Illinois 61801 USA
5. Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory; University of Illinois at Urbana-Champaign; Urbana Illinois 61801 USA