1. Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, 138634, Singapore
2. School of Applied Science, Temasek Polytechnic, 21 Tampines Avenue 1, 529757, Singapore
3. Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.