Bi-functional Cu-MOF/PVDF hybrid membranes: Selective acid fuchsin adsorption and laccase mimics catalysis

In this study, bi-functions of surface adsorption and laccase like catalysis were integrated by the hybrid membranes of Cu-MOF (Cu-2MI) uniformly incorporated polyvinylidene fluoride (PVDF) for the first time, which endow an unexpected utility in surface physical adsorption and chemical catalytic engineering. In which, the loading of Cu-2MI was varied to optimize the surface performance of the membranes. The adsorption conditions were optimized based on batch adsorption experiments, and the adsorption kinetics, isotherms, and thermodynamics were discussed by using theoretical models to elucidate the adsorption mechanism. In addition, the laccase-mimicking catalytic performance of these Cu-2MI/PVDF hybrid membranes was explored based on the colorimetric reaction of 2,4-dichlorophenol (2,4-DP). The laccase-like catalytic kinetics, including K m and V max , were determined, and their catalytic stability under varying pH, temperature, organic solvents, and storage time was systematically tested and compared to that of free laccase. The maximum adsorption capacity of the obtained Cu-2MI/PVDF hybrid membrane for acid fuchsin (AF) is 4789.5 μg cm −2 . Moreover, the hybrid membrane exhibits a good linear relationship in the range of 5.0–750 μM in adrenaline detection, with a detection limit of 3.60 μM. This work highlights the exceptional surface activity and stability of the Cu-MOF/PVDF hybrid membranes, which ensure promising applicability in surface physical and chemical engineering.