1. College of Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350116, P. R. China
2. MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, P. R. China
3. Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, Maryland 20892, United States