1. Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
2. Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
3. Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
4. Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, United States
5. Delaware Biotechnology Institute, Newark, Delaware 19711, United States