1. Department of Chemistry, University College London (UCL), London WC1H 0AJ, U.K.
2. Singapore Bioimaging Consortium (SBIC), Agency for Science Technology and Research (A*STAR), Singapore 138667, Singapore
3. School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, U.K.
4. Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
5. Institute for Materials Discovery, University College London (UCL), London WC1H 0AJ, U.K.