Water-stable europium(III) and terbium(III)-metal organic frameworks as fluorescent sensors to detect ions, antibiotics and pesticides in aqueous solutions

The reliable, convenient and rapid detection methods for various environmental pollutants using fluorescent sensors had attracted great attention. Herein, we reported the assembly and characterizations of two new fluorescent 3D lanthanide metal-organic frameworks (Ln-MOFs), namely [Eu(PMBB)1.5(H2O)2] (Eu-MOF) and [Tb(PMBB)1.5(H2O)2] (Tb-MOF) (H2PMBB = 4,4′-((1,4-phenylenebis(methylene))bis(oxy))dibenzoic acid). The fluorescent sensing results reveal that the two MOFs exhibit effective sensitivity toward Fe3+, Cr2O72−, cefixime (CFX), nitrofurazone (NFZ), imidacloprid (IMI) and nitenpyram (NTP) in aqueous medium. Notably, the Tb-MOF is more sensitive toward MnO4− than Eu-MOF due to the enhanced fluorescence resonance energy transfer (FRET) effect. This work provides the example for more effective designs to employ Ln-MOFs as fluorescent sensors for detection of environmental pollutants in aqueous solution.