Tailored design of hollow spheric Eu-Luminol/ZIF-8 mixed matrix membranes for simultaneous ratiometric sensing and enhanced adsorption of tetracyclines

The increasing concern about tetracyclines (TCs) contamination brings out the development of multifunctional materials to sensitively detect and effectively remove TCs. Herein, a novel Eu-Luminol/ZIF-8 (Eu-L/ZIF-8) heterojunction is rationally designed for the simultaneous capture and ratiometric sensing of TCs. The large specific surface area, hollow and multiple pore structure of Eu-L/ZIF-8 boost the enhanced adsorption for tetracycline (TC, 1115.3 mg g−1), oxytetracycline (OTC, 869.6 mg g−1) and doxycycline (DOX, 862.1 mg g−1). Meanwhile, sensitive ratiometric sensing of TCs is realized by gathering TCs around the sensing center of Eu-L to induce the fluorescence turn-on of Eu3+ (615 nm) and quenching of luminol (435 nm). The detection limit is 5 nM for TC and OTC, 10 nM for DOX, respectively. Furthermore, Eu-L/ZIF-8 is fabricated to mixed matrix membranes (MMMs) for the portable visual sensing and online removal of TCs. The portable sensing of TCs is conducted by a homemade testing kit within 10 min, and the online removal of TCs is realized with a removal efficiency above 90 % in real wastewater. The results demonstrate that Eu-L/ZIF-8 MMMs is a powerful tool for the portable sensing and simultaneous removal of TCs. •A novel multifunctional Eu-Luminol/ZIF-8 (Eu-L/ZIF-8) heterojunction is designed.•Eu-L/ZIF-8 exhibits excellent ratiometric sensing and adsorption capacity to TCs.•Highly porous Eu-L/ZIF-8 mixed matrix membranes (MMMs) is fabricated.•In situ sensing and online removal of TCs is simutaneously realized by the MMMs.•Practical applicability of Eu-L/ZIF-8 MMMs is achieved in real wastewater.