Small-molecular amines fluorescence sensor based on the destruction of an aggregation-induced-emission-active Zn metal-organic framework

In this work, based on the fluorescence changes of Zn-TCPE we report a novel strategy for perceiving harmful amines migrated from packaging printing inks. In an aqueous solution, Zn-TCPE fluorescence is quenched by water molecule coordination. However, after the introduction of nitrogen heterocyclic, aromatic, and aliphatic amines, respectively, competitive coordination substitution and electrostatic interactions with amino groups inhibit the movement of the AIE-active organic ligand, leading to the re-enhancement of fluorescence. Fluorescence restart enables the highly sensitive and selective detection of potentially harmful amines with low detection limits of 18.7–68.5 ​nM. So far, the methods for sensitive sensing of amines based on MOFs destruction-triggered fluorescence "turn-off-on" have seldom been reported up to now. Compared with traditional methods, this sensing method with fluorescence "turn-off-on" is simpler, faster, and more sensitive. The detection results of amines in the actual sample reveal that the fluorescent probe has good application prospects.