One of the great challenges in the post-genome era is to clarify the significance of biological molecules directly in living cells/organisms. The expression and metabolism of these molecules are precisely regulated in terms of time and space. If we can visualize (or manipulate) a molecule in action, it will be possible to acquire biological information that is unavailable when dealing with cell homogenates. One promising approach to achieve this goal, we believe, is to design and synthesize functional sensor molecules,which allow biological information (e.g. Ca2+ influx, enzyme activity, oxidative stress) to be monitored by spectroscopic methods. For this purpose, we have developed a number of fluorescent probes and smart MRI agents for intracellular messengers, and successfully applied them to living cells and organisms. We have also succeeded in developing functional photosensitizers that inactivate target molecules or induce oxidative stress to specific cells.

1. Design, synthesis and biological application of novel sensor molecules for cellular signaling molecules,such as zinc ion, reactive oxygen species, or various enzymes.
2. Design and synthesis of novel MRI probes for in vivo imaging.
3. Development of novel bioluminescence probes.
4. Establishment of a methodology to monitor the behaviors of the proteins of interest with fluorescent molecules.
5. Application of fluorescent probes to optical imaging of cancer.
6. Development of fluorescent probes for diagnostic applications.