A Water-Stable Tb-MOF As a Rapid, Accurate, and Highly Sensitive Ratiometric Luminescent Sensor for the Discriminative Sensing of Antibiotics and D2O in H2O.

Abstract

The design and development of self-calibrating ratiometric luminescent sensors for the fast, accurate, and sensitive discrimination and determination of pollutants in wastewater is highly desirable for public and environmental health. Herein, a 3D porous Tb(III)-based metal-organic framework (MOF), {[Tb(HL)(H2O)2]·x(solv)}n (1), was facilely synthesized using a urea-functionalized tetracarboxylate ligand, 5,5 -(((1,4-phenylenebis(azanediyl))bis(carbonyl))bis(azanediyl))diisophthalic acid (H4L). The activated framework showed a good water stability in both aqueous solutions at a wide pH range of 2-14 and simulated antibiotic wastewaters. Interestingly, this Tb-MOF exhibited dual luminescence owing to the partial energy transfer from the antenna H4L to Tb3+. More importantly, activated 1 (1a) that was dispersed in water showed a fast, accurate, and highly sensitive discrimination ability toward antibiotics with a good recyclability, discriminating three different classes of antibiotics from each other via the quenching or enhancement of the luminescence and tuning the emission intensity ratio between the H4L ligand and the Tb3+ center for the first time. Simultaneously, 1a is a ratiometric luminescent sensor for the rapid, accurate, and quantitative discrimination of D2O from H2O. Furthermore, this complex was successfully used for the effective determination of antibiotics and D2O in real water samples. This work indicates that 1a represents the first ever MOF material for the discriminative sensing of antibiotics and D2O in H2O and promotes the practical application of Ln-MOF-based ratiometric luminescent sensors in monitoring water quality and avoiding any major leak situation.