Selective and Rapid Detection of 4-Nitrophenol in River and Treated Industrial Wastewater by a Luminescent Lanthanide Metal–Organic Framework Sensor
Yang Yang, Zhonghang Chen, Chuya Fu, Sandeep Kumar, Wei Shi, Feiyun Sun, Xuemei Yang, Peng Ren
Abstract
Phenolic organic compounds are widely used industrial chemicals that exist extensively in the environment and have a significant impact on human health. 4-Nitrophenol (4-NP) is a typical phenolic organic compound found in aqueous environments. Efficient detection of 4-NP in wastewater is highly challenging due to the complexity of testing environmental samples. Herein, a luminescent lanthanide metal–organic framework (MOF) sensor based on the Eu 3+ ion {[Eu(HL)(L)(H 2 O)]·2H 2 O} n ( EuMOF; H 2 L = 5-(4 H -1,2,4-triazol-4-yl)benzene-1,3-dicarboxylic acid) was successfully synthesized for efficient 4-NP detection in wastewater. Fluorescence sensing experiments revealed that 4-NP could greatly quench the EuMOF fluorescence. Subsequently, EuMOF was applied to 4-NP detection in distilled water, tap water, river water, and treated industrial wastewater, exhibiting high sensitivity, a fast response within 30 s, high selectivity, excellent reusability, and a low detection limit. Finally, the fluorescence quenching mechanism was explored and attributed to competitive absorption of irradiated light between 4-NP and the ligand.