* Corresponding authors

^a Biophysics Group, Department of Physics and Astronomy, University College London, Gower Street, London, UK
E-mail: ntk.thanh@ucl.ac.uk
Web: http://www.ntk-thanh.co.uk

^b UCL Healthcare Biomagnetics and Nanomaterials Laboratories, 21 Albemarle Street, London, UK

^c UCL Electronic and Electrical Engineering, UCL, Gower Street, London, UK

^d Healthy Infrastructure Research Group, Department of Civil, Environmental & Geomatic Engineering, UCL, Gower Street, London, UK

^e Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

^f Environmental Research Laboratory, ClinicalMicrobiology and Virology, University College London Hospitals NHS Foundation Trust, London, UK

^g Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada