1. Center for Single Molecule Biophysics, Arizona State University, Tempe, AZ 85287, USA.
2. Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA.
3. Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
4. Department of Physics, Arizona State University, Tempe, AZ 85287, USA.
5. School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.