1. Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
2. Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102400, P. R. China
3. School of Medical Technology, Beijing Institute of Technology, Beijing 102400, P. R. China