AIE-based fluorescent probe designed with xanthone as a π-bridge for detecting of ClO^- in pericarp and living cells

The role of ClO^- in the physiological functioning of organisms is significant. In this paper, the four fluorescent probes HON_x (HON₁, HON₂, HON₃ and HON₄) were prepared based on oxyanthracene through the introduction of different substituents, and their photophysical properties were investigated, among which the AIE effect of HON₁ was the most significant, and therefore the fluorescent "turn-off" ClO^- probe HON₁-CN was chosen to be prepared by constructing the ClO^- recognition site hydrazone bond at HON₁. The ClO^- recognises the hydrazone group in the probe HON₁-CN, and when the hydrazone bond is broken, the aldehyde group is released, generating HON₁ with yellow fluorescence. The probe HON₁-CN is highly selective and stable for the detection of ClO^- with a detection limit of 0.48 μM and a more than 10-fold increase in fluorescence intensity when the fluorescence is 'switched on', and to a lesser extent, the probe is also very good for the detection of hypochlorite ClO^- in the pericarp. Finally, HON₁-CN has also been used to detect the presence of ClO^- in HeLa cells and zebrafish.