1. Department of Chemistry, University of North Bengal, Darjeeling734013, India
2. Department of Chemistry, Government General Degree College at Kushmandi, Dakshin Dinajpur733121, India
3. Nanobiology and Phytotherapy Laboratory, Department of Botany, University of North Bengal, Siliguri734013, West Bengal, India
4. Department of Chemistry, University of Gour Banga, Malda732103, India
5. Department of Chemistry, Alipurduar University, Alipurduar736122, India