**Acknowledgements**

PKN acknowledges the financial support from the Department of Science and Technology, Government of India (DST-GoI), with sanction Order No. SB/S2/RJN-043/2017 under Ramanujan Fellowship. This work was also partially supported by Indian Institute of Technology Madras to the 2D Materials Research and Innovation Group and Micro-Nano and Bio-Fluidics Group under the funding for Institutions of Eminence scheme of Ministry of Education, GoI [Sanction. No: 11/9/2019-U.3 (A)]
