Novel Multifunctional Zn Metal–Organic Framework Fluorescent Probe Demonstrating Unique Sensitivity and Selectivity for Detection of PA and Fe³⁺ Ions in Water Solution

A novel metal–organic framework {Zn₂(tpt)₂(tad)₂·H₂O} (tpt = 2,4,6-tri­(pyridin-4-yl)-1,3,5-triazine, H₂tda = 2,5-thiophene dicarboxylic acid) with a 3-fold interpenetrating 3D framework was successfully synthesized under hydrothermal conditions. As expected, 1 displays excellent luminescence and can stably exist in different pure organic solvents and acid–base solution. 1 can be considered as an ultrasensitive sensor for detection of Fe³⁺ ions and PA with high selectivity by fluorescence quenching behaviors. Meanwhile, the fluorescence test plates show the visible color change of Fe³⁺ ions which can be easily observed by the naked eye in the detection process, which makes Fe³⁺ ions more easily recognized than various metal ions. In addition, the mechanism of fluorescence quenching is also further discussed.