1. Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, India
2. Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
3. School of Environmental Science, Jawaharlal Nehru University, New Delhi 110067, India
4. Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27695, USA