1. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication
2. CAS Center for Excellence in Nanoscience
3. National Center for Nanoscience and Technology
4. Beijing 100190
5. P. R. China
6. School of Chemistry
7. Beijing Advanced Innovation Center for Biomedical Engineering
8. Beihang University
9. Beijing 100191
10. Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano Devices
11. Department of Physics
12. Renmin University of China
13. Beijing 100872