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 (HON, HON, HON and HON) were prepared based on oxyanthracene through the introduction of different substituents, and their photophysical properties were investigated, among which the AIE effect of HON was the most significant, and therefore the fluorescent "turn-off" ClO probe HON-CN was chosen to be prepared by constructing the ClO recognition site hydrazone bond at HON. The ClO recognises the hydrazone group in the probe HON-CN, and when the hydrazone bond is broken, the aldehyde group is released, generating HON with yellow fluorescence. The probe HON-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, HON-CN has also been used to detect the presence of ClO in HeLa cells and zebrafish.