1. Department of Chemical and Biomolecular Engineering; National University of Singapore; Singapore 117585 Singapore
2. Environmental Research Institute; National University of Singapore; Singapore 117411 Singapore
3. Department of Chemistry and Division of Biomedical Engineering; Hong Kong University of Science and Technology; Clear Water Bay Kowloon Hong Kong
4. SCUT-HKUST Joint Research Laboratory; Guangdong Innovative Research Team; State Key Laboratory of Luminescent Materials and Devices; South China University of Technology; Guangzhou 510640 China
5. Institute of Materials Research and Engineering; Agency for Science; Technology and Research (A*STAR); Singapore 117602 Singapore