1. Chemistry Research Laboratory Department of Chemistry University of Oxford Oxford OX1 3TA UK
2. Department of Chemistry and Institute of Physics of Living Systems University College London 20 Gordon Street London WC1H 0AJ UK
3. Institute for Bioengineering of Catalonia The Barcelona Institute of Science and Technology 08028 Barcelona Spain
4. Department of Chemical Sciences Faculty of Pharmacy University of Porto Portugal
5. EPSRC/Jeol Centre for Liquid Phase Electron Microscopy University College London London WC1H 0AJ UK