Reversible Ratiometric Fluorescent Probe for Sensing Bisulfate/H2O2 and Its Application in Zebrafish.

Herein, a novel near-infrared fluorescent probe for ratiometric detection of bisulfate was designed and developed based on a conjugation of naphthopyran-benzothiazolium system. The sensor showed excellent selectivity, high sensitivity and a rapid response toward bisulfite in aqueous solution. Upon the addition of HSO3-, the sensor displayed 37-fold (I520/I630) fluorescence intensity enhancement, accompanied by an apparent color change from violet to colorless, suggesting that the sensor can be used to detect HSO3- with "naked-eye". Notably, the addition product can be applied to the design of regenerative chemodosimeters based on the H2O2 promoted elimination of bisulfite and recovery of probe 1. Further cell and zebrafish imaging experiment demonstrated that the sensor could image the bisulfite/H2O2 redox cycle in biological system with ratiometric manners.