Development of receptor-sensitive near-infrared absorbing azabodipy dye for glucose sensors

With the aim of developing a subcutaneously implantable optical sugar sensor that can continuously measure blood glucose levels, we have developed a novel dye that changes the absorption spectrum in the near-infrared wavelength region by forming a complex with glucose receptors. As a result of synthesizing six types of azaBODIPY dyes having a catechol moiety, it was found that the absorption spectrum of each dye changes due to the complex formation with phenylboronic acid (PBA), which is a model compound of sugar receptors. Among the receptor-sensitive dyes we synthesized, thienyl-azaBODIPY, in which three thienyl groups were introduced into the molecule, showed the maximum absorption wavelength (732 nm) on the longest wavelength side. It was found that when glucose was added to a solution containing thienyl-azaBODIPY and the glucose receptor bisbenzoboroxol (bisBB), the absorbance in the near-infrared wavelength region changed significantly depending on the glucose concentration.