A Fluorescent Probe Based on the Hydrazone Schiff Base for the Detection of Zn and its Application on Test Strips.

A novel fluorescent probe SHK for Zn detection was designed based on the hydrazone Schiff base, successfully synthesized by Suzuki coupling and condensation reactions. The probe SHK in DMSO/HO showed extremely weak fluorescence. However, the solution exhibited an intensive yellow-green emission with the introduction of Zn. In contrast, negligible fluorescence change was observed when other metal ions were added, suggesting a high selectivity of SHK for Zn detection. The Job's Plot analysis revealed that a 1:1 stoichiometric adduct SHK-Zn formed during the Zn sensing. The binding constant of the complex was determined to be 184 M, and the detection limit for Zn was calculated to be 112 µM. Moreover, the probe SHK achieved selective fluorescence sensing for Zn on test strips, which guaranteed its practical application prospect.