[1] Lanzhou Univ, Inst Nanosci & Nanotechnol, Sch Phys Sci & Technol, Lanzhou 730000, Peoples R China
[2] Lanzhou Univ, Inst Pathogen Biol, Sch Basic Med Sci, Lanzhou 730000, Peoples R China
[3] Lanzhou Univ, Res Inst Biomed Nanotechnol, Sch Basic Med Sci, Lanzhou 730000, Peoples R China
[4] Chinese Acad Sci, Beijing Inst Nanoenergy & Nanosyst, Beijing 100085, Peoples R China
[5] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA