1. CAS Key Laboratory of Standardization and Measurement for Nanotechnology
2. CAS Center for Excellence in Nanoscience
3. National Center for Nanoscience and Technology
4. Beijing 100190
5. People's Republic of China
6. Beijing Key Laboratory of Microanalytical Methods and Instrumentation
7. MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology
8. Department of Chemistry
9. Tsinghua University
10. Beijing 100084