1. Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 106, India
2. Department of Microbiology, St. Xavier’s College, 30, Mother Teresa Sarani, Kolkata 700016, India
3. Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India
4. Institute for Condensed Matter Physics and Laboratory for Emerging Nanometrology, TU Braunschweig, Mendelssohnstrasse 3, Braunschweig 38106, Germany