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

Highlights: • A novel Tb-based MOF [Tb₂(BTZ)(μ₂-H₂O)(μ₃-OH)₂] was synthesized. • This compound displays excellent chemical stability and water in the wide pH range. • It exhibits a multiresponsive fluorescence sensing behavior. • It can highly and sensitively detect of MnO₄⁻ nitroaromatic explosives. 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 (0.16mM). 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 K_sv=3.38×10⁴M^-1, and low detection limit of 0.20mM. 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.