Michael and Schiff-Base Reactions-Assisted Fluorescence Sensor Based on the MOF Nanosheet Microspheres for the Effective Discrimination and Detection of Hydroquinone and Catechol
Jiayi Fan, Jinfan Li, Chunyan Liu, Mengyun Lu, Xinwen Jia, Wuduo Zhao, Ajuan Yu, Shusheng Zhang
Abstract
A novel sensing platform was constructed for the recognition and identification of dihydroxybenzene isomers based on the MOF-0.02TEA fluorescence sensor with the morphology of nanosheet microspheres through coordination modulation. Based on the sensing principle that the amino group on the MOF-0.02TEA can make the Michael reaction with o -benzoquinone and p -benzoquinone, which were individually the oxidation intermediate of catechol and hydroquinone, the fluorescence intensity of MOF-0.02TEA could be quenched through the inner filter effect (IFE) without the interference from resorcinol. Besides, catechol and hydroquinone could be further distinguished with the assistance of the Schiff-base reaction by introducing o -phenylenediamine (OPD) to the detection system. The MOF-0.02TEA sensor exhibited good selectivity, and the detection limits for catechol and hydroquinone were 90.5 nmol/L and 0.52 μmol/L (S/N = 3), respectively. Moreover, the sensor could be used for the determination of dihydroxybenzene isomers in tap water and lake water.