Highly sensitive detection of tetracycline and Fe3+ and for visualizable sensing application based on a water-stable luminescent Tb-MOF

Excessive use of tetracycline (TC) or Fe3+ ions aggravates environmental pollution and threatens human health seriously. A water-stable 3D Tb-MOF ([Tb2(L)3]·2H2O, 1-Tb) is reported by employing H2L (5-(pyrazin-2-yl)isophthalic acid) as bridging ligands. The MOF is a dual-functional luminescence sensor for the detection of TC and Fe3+ in aqueous media with good sensitivity and selectivity even in the presence of common pollutants. Moreover, a low limit of detection and a high quenching constant obtained from the linear range for TC and Fe3+ detection are 0.51 μM, 1.47 × 104 M−1 and 0.78 μM, 7.73 × 103 M−1, respectively. The possible quenching mechanism is discussed by PXRD, UV–vis absorption spectroscopy, luminescence lifetime, SEM, and XPS in detail. The results showed that the high quenching efficiency is attributed to the competitive absorption of excitation energy mechanism. Furthermore, the MOF was successfully fabricated as a strip-shaped film (1-Tb-PVDF) with a visualized luminescence response under irradiation with a UV lamp, providing a simple tool for the rapid detection of TC and Fe3+ in aqueous solutions. This work provides a new dual-functional material for detecting the TC and Fe3+ in water.