1. Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India
2. Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh, India
3. Department of Chemistry, National Institute of Technology Agartala, Agartala 799 046, Tripura, India
4. Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India