1. Fluorescence Research GroupSingapore University of Technology and Design 8 Somapah Road Singapore 487372 Singapore
2. CAS Key Laboratory of Separation Science for Analytical ChemistryDalian Institute of Chemical PhysicsChinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
3. Department of PhysicsKings College London London WC2R 2LS UK
4. Department of ChemistryNational University of Singapore 21 Lower Kent Ridge Rd Singapore 119077 Singapore
5. School of Physics and Telecommunication EngineeringSouth China Normal University Guangzhou 510006 China
6. MOE Key Laboratory of Macromolecular Synthesis and FunctionalizationDepartment of Polymer Science and EngineeringZhejiang University Hangzhou 310027 China