Laccase–copper phosphate hybrid nanoflower as potent thiazole remediation agent

Abstract

The increase in the global population in recent years has caused a fast increase in pollution problems worldwide. One of these problems is emerging pollutants, which are a class of human-made organic compounds that have been detected in various water bodies. To develop a recyclable, reusable, and efficient material for the degradation of these pollutants, we report the synthesis, characterization and application of hybrid nanoflowers imbedded with laccase enzymes. These copper phosphate-laccase nanomaterials had a spherical flower-like shape, a surface area of 53.46 m2/g, and a mean pore size of 10.58 nm. When tested against a panel of diverse compounds, the hybrid nanoflowers were able to degrade a number of emerging pollutants, including 2-mercaptobenzothiazole (MBT), caffeic acid, thiabendazole, cimetidine, and sulfamethoxazole, with efficiencies of 97 %, 97.0 %, 78.1 %, 72.3 %, and 51.3 %, respectively. For 2-mercaptobenzothiazole (MBT), we identified the intermediate produced during the degradation process. In addition, the nanoflowers were able to degrade >90 % MBT in a spiked ground water sample. Furthermore, we tested the recyclability and storage stability of the hNFs for the degradation of MBT and found that they could be reused for five cycles and stored for 21 days at 4 °C. Our results suggest that laccase-embedded hybrid nanoflowers to be potent remediation agents for the degradation of thiazole as well as other emerging pollutants. Also, the successful immobilization of laccase on hybrid nanoflowers shown in the present study can allow for the efficient recycling of laccase enzymes for multiple degradation cycles leading to potential scaling up and building of a bioreactor.