Rational design of dual-channel response fluorescent probe and its application for highly efficient biothiols imaging in living samples

Biothiols have the function of maintaining redox balance in organisms and play critical roles in human pathophysiology. This work reported a highly sensitive dual-channel responsive fluorescent probe SKY-NBD utilized for the detection of biothiols in vitro and in vivo. By incorporating the NBD-Cl with the other fluorophore dihydrocyclopentachromene derivative (SKY-OH), the sensitive probe was successfully formulated. Ascribe to the strong electron-withdrawing effect of NBD group, SKY-NBD had almost no fluorescence. Afterwards the supplement of Cys or Hcy, SKY-NBD rapidly gave significantly fluorescent enhancement in both the red and green channels, which was attributed to the release of fluorescent groups SKY-OH and amine-substituted NBD (NBD-NR). However, upon exposure to GSH, only a strong red-channel emission established, revealing the release of SKY-OH. Subsequently, the SKY-NBD probe was effectively utilized for high-quality image of biological thiols in living cell and zebrafish larva. Compared with other NBD-Cl probes, SKY-NBD achieved highly sensitive dual-channel detection of biothiols. Heretofore, we had successfully erected a dual-channel responsive fluorescent probe for the recognition of biothiols. The probe SKY-NBD holds great potential for studying biothiol-related diseases in living system.