Zhaowei Chen1,2,3, Di Wen4,5, Zhen Gu6,7,8,9. 1. MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, 350108, China. chenzw@fzu.edu.cn. 2. Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA. chenzw@fzu.edu.cn. 3. California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA. chenzw@fzu.edu.cn. 4. Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA. 5. California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA. 6. Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA. guzhen@ucla.edu. 7. California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA. guzhen@ucla.edu. 8. Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA, 90095, USA. guzhen@ucla.edu. 9. Center for Minimally Invasive Therapeutics, University of California, Los Angeles, CA, 90095, USA. guzhen@ucla.edu.