Cu-MOF nanosheets with laccase-like activity for phenolic compounds detection and dye removal

In this study, a Cu-MOF nanozyme has been synthesized using 2-methylimidazole coordinated with copper ions for detecting phenolic compounds and removing dyes. The Cu-MOF nanozyme exhibited robust laccase-like catalytic performance in alkaline conditions, high temperature, and under high salt concentrations. Acceptable selectivity and affinity (K-m = 0.14 mM) were observed for the 2,4-dichlorophenol (2,4-DP) substrate in the Cu-MOF nanozyme, allowing for its application in the quantitative detection of 2,4-DP. The limit of detection was determined to be 9.0 x 10(-4) mM with a linear range of 2.5 x 10(-3)-8.0 x 10(-2) mM. Finally, the colorimetric method developed was employed for detecting 2,4-DP in two water samples with satisfactory spiked recoveries (88.7 %-95.9 %). Importantly, the synthesized Cu-MOF nanozyme can efficiently remove two organic dyes (malachite green and congo red) simultaneously, and the developed system is able to cope with complex real-world applications where wastewater contains multiple organic dyes. The Cu-MOF nanozyme, with its simple synthesis, low cost, high catalytic activity, good stability, and high substrate selectivity, is a promising candidate for water pollution treatment and rapid detection. In addition, the present study introduces a versatile approach for mimicking the catalytic center of biological enzymes by combining 2-methylimidazole with metal ions.