1. Johannes Kepler University, Biophysics Institute, Gruberstrasse 40, 4020 Linz, Austria.
2. London Centre of Nanotechnology, University College London (UCL), 17-19 Gordon Street, London WC1H 0AH, UK.
3. Department of Electronic and Electrical Engineering, UCL, Torrington Place, London WC1E 7JE, UK.
4. Department of Physics and Astronomy, UCL, Gower Street, London WC1E 6BT, UK.
5. Keysight Laboratories, Keysight Technologies Inc., Gruberstrasse 40, 4020 Linz, Austria.
6. Department of Physics, ETH, Zurich CH-8093, Switzerland.
7. Institut de Physique, École polytechnique fédérale de Lausanne, Lausanne CH-1015, Switzerland.
8. Paul Scherrer Institut, Villigen CH-5232, Switzerland.
9. Bio Nano Consulting, Gridiron Building, One Pancras Square, London N1C 4AG, UK.