1. Department
of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive, Singapore 117576
2. Department
of Chemistry, Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
3. 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
4. Institute of Materials Research Engineering, 3 Research Link, Singapore 117602