1. Singapore Bioimaging Consortium; Agency for Science; Technology and Research (A* STAR); 138667 Singapore
2. Department of Chemistry; National University of Singapore; 117543 Singapore
3. State Key Laboratory of Chemo/Biosensing and Chemometrics; College of Chemistry and Chemical Engineering; Hunan University; Changsha 410082 Hunan P. R. China
4. Institute of Materials Research and Engineering; Agency for Science; Technology and Research (A* STAR); 117602 Singapore
5. Center for Functional Materials; NUS (Suzhou) Research Institute; Suzhou Jiangsu 215123 P. R. China