1. Biophysics Group, Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, U.K.
2. UCL Healthcare Biomagnetic and Nanomaterials Laboratories, 21 Albermarle Street, London W1S 4BS, U.K.
3. Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis, #8-03, Singapore 138634
4. Institute of High Performance Computing, Electronics and Photonics Department, 1 Fusionopolis Way, Connexis North, #16-16, Singapore 138632
5. Department of Chemistry, National University of Singapore, Block S8, Level 3, 3 Science Drive 3, Singapore 117543
6. School of Engineering and Science, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs QLD 4556, Australia