1. Department of Applied ChemistryFaculty of Science and TechnologyKeio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan
2. Graduate School of Arts and SciencesThe University of Tokyo 3-8-1 Komaba Meguro-ku Tokyo 153-8902 Japan
3. Department of ChemistryFaculty of Science and TechnologyKeio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan
4. Molecular Imaging Program at StanfordBio-X ProgramStanford University School of Medicine 3155 Porter Dr. Palo Alto CA 94304 USA
5. National Institute of Advanced Industrial Science and Technology (AIST)Research Institute for Environmental Management Technology 16-1 Onogawa Tsukuba 305–8569 Japan