A turn-off fluorescent chemical sensor based on a thiazole-Schiff base structure for highly selective and accurate detection of Cu in living cells.

A Schiff base fluorescent probe, HTT, based on a sulfonylhydrazone structure was designed and synthesized for the sensitive and selective detection of Cu. The probe HTT exhibits good anti-interference performance toward Cu in the presence of a variety of metal ions. After the addition of Cu, it can quickly respond within 40 seconds, and the fluorescence detection limit is 1.10 nM. The coordination ratio of probe HTT and Cu is 2 : 1, and the coordination reaction between CN, SO and Cu limits the formation of hydrogen bonds between the hydroxyl group and CN, disrupting the spatial coplanar effect of the probe molecule and thereby inducing fluorescence quenching. The probes can be recovered and reused using EDTA for the detection of Cu. The probe was also applied to the successful monitoring of Cu in living cells and real water samples.