Ni-Based Metal–Organic Framework Derived from 2,6-Bis(1H-Pyrazol-1-yl)Isonicotinic Acid and its Sensing Performance

Abstract

Metal–Organic Frameworks (MOFs) are a class of highly promising antibiotic sensing materials. However, the practical applications of MOF-based fluorescent probes are limited due to their drawbacks, such as insufficient selectivity, weak anti-interference ability, and poor thermal stability. In this study, using Ni2+ as the metal core and 2,6-bis(1H-pyrazol-1-yl)isonicotinic acid (HBPIA) as the organic ligand, a nickel-based metal–organic framework [Ni(BPIA)(H2O)2]+·[Ni(BPIA)Cl2]− (1) was prepared via a facile solvothermal method. Its crystal structure was analyzed in detail by single-crystal X-ray diffraction. The basic unit of 1 is a chain structure with alternating Ni-centered positively charged octahedra and negatively charged octahedra connected by BPIA ligands: ─ [Ni(O3N3)]Octa+ ─BPIA─ [Ni(ON3Cl2)]Octa− ─BPIA─. The chains are orderly stacked with each other through electrostatic attraction and hydrogen bonding to form the crystal. Complex 1 exhibits good thermal stability and remarkable fluorescence emission properties, and shows highly sensitive fluorescence recognition ability toward the antibiotic marbofloxacin (MBF), with a calculated detection limit as low as 14.19 nM. Meanwhile, it has excellent anti-interference performance and can selectively recognize MBF in the presence of other 10 antibiotics, demonstrating the potential for detecting trace MBF in complex water environments. This work represents the first application of MOFs for the fluorescence sensing detection of MBF, offering a novel and promising strategy for the rapid monitoring of MBF residues in environmental waters.