Environmentally Friendly and Recyclable Natural-Mediator-Modified Magnetic Nanoparticles for Laccase-Catalyzed Decolorization

Abstract EN

The high cost, potential toxicity, and possible enzyme inhibition ability of artificial mediators have limited the large-scale application of laccase (Lac)/mediator systems.

Here, sinapic acid (SA), a natural mediator, was covalently attached to amino-functionalized magnetic nanoparticles (MNPs) via amide bond formation.

The as-prepared SA@MNPs were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, and thermogravimetric analysis.

The SA@MNPs were then applied to evaluate the activity of the immobilized mediator for Lac-catalyzed dye decolorization using indigo carmine (IC) as a model dye.

When SA and SA@MNPs were used as Lac mediators, IC decolorization yields of ∼93% and 96%, respectively, were obtained after 60 min.

Moreover, SA@MNPs exhibited an IC decolorization yield of ∼90% after being reused for 8 cycles.

The Lac/SA@MNP system was shown to degrade IC by breaking down the chromophoric group.

The easy recyclability, good reusability, nontoxicity, and relatively low cost of SA@MNPs make this immobilized natural mediator a promising tool for dye treatment.