A stable terbium(III) metal-organic framework as a dual luminescent sensor for MnO4− ions and nitroaromatic explosives

Abstract

A new terbium(III) metal-organic framework [Tb2(BTZ)(μ2-H2O)(μ3-OH)2] (ZH-101, H2BTZ ​= ​3.5-bis(4’-carboxy-phenyl)-1,2,4-triazole) was synthesized with BTZ ligands under solvothermal conditions for the luminescent study. It is constructed of [Tb2(μ2-O)(μ3-O)2]n 2D layered structure and is further connected by BTZ ligands with rich triazole-N sites to form a water-stable 3D net framework. ZH-101 displays excellent chemical stability in common organic solvents and water in the wide pH range of 0–11. The luminescence test experiment of ZH-101 in water containing different anions shows selective fluorescence quenching for MnO4− with low detection limit (0.16 ​mM). In addition, ZH-101 also displays excellent luminescence stability in different solvents and can selectively detect nitroaromatic explosives in DMF solutions, especially for 4-nitrophenol with Ksv ​= ​3.38 ​× ​104 ​M-1, and low detection limit of 0.20 ​mM. It still retains original fluorescence intensity and chemical stability after five cycles experiments, exhibiting remarkable long-term cycle and reversibility. Therefore, ZH-101 is a competitive and promising candidate for sensing MnO4− ions and nitroaromatic explosives.