Design and Construction of a Mixed-Ligand Coordinated Fluorescent Complex and Its Application for Sensing Ions, Antibiotics, and Pesticides in Aqueous Solution

In this work, a fluorescent complex [Zn(NTD)2(DTP)2(H2O)2]·(H2O)0.8(Complex Zn), (H2NTD = 1,4-naphthalenedicarboxylic acid and DTP = 3,5-di(1,2,4-triazol-1-yl)pyridine) was synthesized. The fluorescent complex was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and thermogravimetric, elemental, infrared spectroscopy, and fluorescence analyses. In the fluorescence sensing tests, Complex Zn exhibited excellent fluorescence quenching efficiency towards Fe3+, MnO4−, Cr2O72−, nitrofurantoin, and imidacloprid in aqueous media. A mechanism investigation suggested that the fluorescence quenching caused by the quenchers toward the sensor was due to the inner filter effect and the fluorescence resonance energy transfer effect in the fluorescent sensing process.