1 Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, UK.
2 Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, UK.
3 Centre for Nano Science and Engineering (CeNSE), Indian Institute of Science, Bangalore, Karnataka, India.
4 TCS Research and Innovation, Tata Consultancy Services, Bangalore, India.
5 Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, UK. L.Paterson@hw.ac.uk.