Dye removal by laccase-functionalized micromotors

Laccase-based poly(3,4-ethylenedioxythiophene)-polypyrrole/Pt (PEDOT-PPy-COOH/Pt) micromotors were electrosynthesized, characterized and applied for the decolorization of azo dyes widely used in the textile industry and found in textile wastewater. These laccase-based micromotors, due to their self-propulsion capabilities, were successfully used for the degradation of dyes by the improved activity of the on-the-fly immobilized laccase enzyme compared to that of the free enzyme. The Pt layer of the micromotor pro-duced O-2 by breaking down H2O2 and enabled the micromotor to move, while the carboxyl groups in the pyrrole units were used for the binding of laccase enzyme effectively, using the EDC/NHS coupling reaction. Enzyme stability studies were carried out, showing improved stability of the on-board immo-bilized enzyme at different pH and temperature conditions without a significant loss in affinity to the substrate. The overall dye removal capacity of the laccase-functionalized micromotors was demonstrated using dyes with 76-94% of decolorization efficiencies in comparison with those found using the free en-zyme approach with lower decolorization efficiencies of about 34-55%. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Laccase-based micromotors were synthesized and used for decolorization of azo dyes in textile wastewater, showing improved dye removal capacity compared to the free enzyme approach. The stability of the immobilized enzyme was enhanced, resulting in higher decolorization efficiencies of 76-94% compared to 34-55% using free enzyme.