1. Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
2. Shenzhen Key Laboratory for Molecular Imaging, Shenzhen 518055, People’s Republic of China
3. Research Center for Biosensors and Medical Instruments, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People’s Republic of China
4. Department of Physics, University of Vermont, Burlington, Vermont 05405, USA