1. Department of Biotechnology , Visva-Bharati University , Santiniketan , West Bengal 731 235 , India
2. Department of Physics , Visva-Bharati University , Santiniketan , West Bengal 731 235 , India
3. School of Chemical Sciences , Central University of Gujarat , Sector-29 , Gandhinagar , Gujarat 382030 , India
4. Department of Chemistry , Visva-Bharati University , Santiniketan , West Bengal 731 235 , India
5. Department of Chemistry , Sammilani Mahavidyalaya , Baghajatin , Kolkata , West Bengal 700094 , India