Magnetic nanoparticles encapsulated laccase nanoflowers: evaluation of enzymatic activity and reusability for degradation of malachite green

• Published in: Water science and technology Vol. 81; no. 1; pp. 29 - 39
• Main Authors: Sun, Tingting, Fu, Meihua, Xing, Jinfeng, Ge, Zhiqiang
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01.01.2020
• Subjects: Access; Adsorption; Aquaculture; Aqueous solutions; Crystals; Degradation; Efficiency; Electron microscopy; Encapsulation; Enzymatic activity; Enzyme activity; Enzymes; Enzymes, Immobilized; Fourier transforms; Iminodiacetic acid; Iron oxides; Laccase; Magnetite Nanoparticles; Malachite green; Methods; Microscopy; Nanocrystals; Nanoparticles; Pollutants; Proteins; Reaction time; Rosaniline Dyes; Scanning electron microscopy; Spectrum analysis; Transmission electron microscopy; China
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2020.068

Magnetic laccase nanoflowers (MNFs-Lac) were successfully prepared through encapsulating Fe O magnetic nanoparticles into the interior of laccase nanoflowers by grafting N-(phosphonomethyl)iminodiacetic acid (PMIDA) as an interconnecting bridge between the magnetic nanoparticles and copper ions. The characterizations by scanning electron microscopy and transmission electron microscopy showed that MNFs-Lac were spherical, porous and flower-like crystals with diameters of ∼10 μm, and Fe O nanoparticles were encapsulated in the interior of MNFs-Lac evenly. The enzymatic activity and reusability of MNFs-Lac were evaluated based on the degradation efficiency for malachite green (MG). The degradation parameters, concerning initial MG concentration, dosage of MNFs-Lac, reaction temperature, pH value and reaction time, were optimized through single-factor experiments. Under the optimal conditions, 25 mg·L MG can be degraded almost completely by 1.5 g·L MNFs-Lac within 15 min. When the MNFs-Lac were reused for 18 times, the degradation efficiency of MG was still as high as 90%. These results suggested that the modified preparation method improved greatly the reusability of MNFs-Lac, which made them more suitable to degrade MG in a water environment.