1. Centre for Nanoscience and Nanotechnology, Panjab University, Sector 14, Chandigarh 160014, India
2. Department of Chemistry & Centre for Advanced Studies in Chemistry, Panjab University, Sector 14, Chandigarh 160014, India
3. Department of Applied Sciences, University Institute of Engineering and Technology (U.I.E.T.), Panjab University, Sector 25, Chandigarh 160014, India