1. College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
2. Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
3. Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
4. Department of Bioengineering, University of California at Berkeley, Berkeley, California 94720, United States