1. Key Laboratory of Molecular Nanostructure and Nanotechnology Beijing National Laboratory for Molecular Sciences CAS Research/Education Center for Excellence in Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China
2. University of the Chinese Academy of Sciences Beijing 100190 P. R. China
3. Key Laboratory of Analytical Chemistry for Living Biosystems Beijing National Laboratory for Molecular Sciences National Centre for Mass Spectrometry in Beijing Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China
4. State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China