Advantages
- A group of molecules that absorb light around 700 nm, which is in the near-infrared region, and show fluorescence at 800-900 nm.
- High molar extinction coefficient (ε) and large Stokes shift
- Strong fluorescence not only in solutions but also in thin films.
Background and Technology
Compounds that absorb light in wavelength regions invisible to the naked eye, such as the ultraviolet and near-infrared regions, are expected to be useful as security inks and sensor materials. Because of the weak absorption of hemoglobin and water and the high permeability of cellular tissues, the near-infrared region is called as the optical window of living systems. Therefore, molecules that absorb and emit light in this region have potential applications in the biological fluorescence imaging, photodynamic therapy, and photothermal therapy.
| Conventional near-infrared dyes are known to include nanoparticles containing rare earth metals, quantum dots containing lead or cadmium, etc., and metal complexes containing rare metals such as iridium. In contrast, metal free-organic emitters can be expected to have advantages, such as flexibility, light weight, low cost, and low toxicity. There are limited examples of organic dyes that exhibit absorption and fluorescence properties in the near-infrared region, and typical examples thereof are cyanine-based or benzobis(thiadiazole)-based dyes. However, near-infrared organic emitters having both a high molar extinction coefficient (ε) and a large Stokes shift is rare. We have developed a new tropylium-based near infrared emitters having both a high molar extinction coefficient (ε) and a large Stokes shift, and a method for their synthesis. |
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Patents
- Pending (Unpublished yet)
Principal Investigator
Masahito MURAI (Graduate School of Science, Nagoya University)
Current Stage and Next Step
- Currently, new tropylium-based near-infrared fluorescent dyes have been synthesized and their fundamental photophysical properties have been evaluated.
- We are looking for collaborative partner companies to study, evaluate, and develop applications using these compounds and derivatives.
Project.BK-04566