1. PG and Research Department of Chemistry, Presidency College (Autonomous), Chennai 600005, Tamil Nadu, India
2. Department of Chemistry, St. Xavier’s College (Autonomous), Tirunelveli 627002, India
3. UNESCO-UNISA Africa Chair in Nanoscience’s/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P.O. Box 392, Pretoria, South Africa