A New [δ-PMoVMoVI11O40]-Based Hybrid as Multifunctional Fluorescent Sensor for Detecting Cations, Anions, and Antibiotics in Aqueous Solution

A new POM-based hybrid, [δ-H4PMoVMoVI11O40](L)5·5H2O (L = 4-methylpyridine-4-yl-1,8-naphthalene dicarboxylamide), was synthesized under hydrothermal conditions and characterized by IR spectroscopy, powder X-ray diffraction, and X-ray photoelectron spectroscopy. This hybrid can acts as multifunctional fluorescent sensor to detect metal cation (Fe3+), anions (Cr2O72– and CrO42–), and antibiotics (NFT = nitrofurantoin, NIT = nitrofurazone, OXY = oxytetracycline) in aqueous environment. The detection limits of the POM-based hybrid were 8.9×10–5, 2.1×10–4, 2.2×10–4, 1.4×10–4, 6.9×10–4, and 6.1×10–4 mol/L for Fe3+, Cr2O72–, CrO42–, NIT, NFT, and OXY, respectively. Furthermore, the quenching mechanism between the POM-based hybrid and the different analytes can be regarded as energy competitive absorption.