1. Fluorescence Research Group, Science, Math and Technology Cluster, Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore, Singapore
2. Department of Chemistry, School of Science, Hainan University, Haikou 570228, China
3. Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Shanghai Key Laboratory of Functional Materials Chemistry, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China