Highly selective and sensitive long fluorescence lifetime polyurethane foam sensor based on Tb-complex as chromophore for the detection of H2PO4- in water

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Jun 15:217:86-92. doi: 10.1016/j.saa.2019.03.078. Epub 2019 Mar 23.

Abstract

Developing novel rare-earth complexes to rapidly and reliably sensing anions in pure water is highly challenging. Here, a series of long fluorescence lifetime polyurethane foam bonded Tb(BAA)3 chromophore porous material (Tb-PUFs) have been designed and synthesized via a simple one-step co-polycondensation reaction as an efficient fluorescent sensor for H2PO4- in pure water. All Tb-PUFs exhibited strong green emission and long fluorescence lifetime in water, which was ascribed to Tb-complex can be dispersed very well in polyurethane foam, effectively avoiding the emission quenching of Tb3+ ions caused by water molecules vibration. The titration experimental results showed that precursor Tb(BAA)3 can effective recognize F-, CH3COO-, and H2PO4- in DMSO solution. Interestingly, Tb-PUFs can only selectively recognize H2PO4- in pure water, this phenomenon can be explained that H2PO4- is acidic, and can occur deprotonation with -NH group of ligand BAA, thus making the fluorescence quenching effect was more sensitive for H2PO4- in pure water. In addition, the sensing ability of Tb-PUFs for H2PO4- is highly reversible by washing them with deionized water for three times. In a word, all results implied that Tb-PUFs was an excellent candidate for H2PO4- ions detection selectively in pure water.

Keywords: Fluorescence probe; Fluorescence quenching; H(2)PO(4)(−) detection; Terbium complexes.