1. Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K.
2. Biophysics Group, Department of Physics, Faculty of Science, Mansoura University, Mansoura 35511, Egypt
3. Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K.
4. School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K.