Water-Stable Europium(III) and Terbium(III)–Metal Organic Frameworks as Fluorescent Sensors to Detect Inorganic Ions, Antibiotics and Pesticides in Aqueous Solutions

Abstract

Development of reliable, convenient and rapid detection methods for environmental pollutants using fluorescent sensors has 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 structural data veal that both of the structures constructed in 3D network, in view of topology, Eu-MOF is in a bnn net and Tb-MOF is in an mab net. The fluorescent sensing results revealed 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- in fluorescent quenching tests than Eu-MOF due to the Forstert resonance energy transfer (FRET) effect. This work provides the first example to employ MOFs as fluorescent sensors for detection of IMI in aqueous solution.