Dual-functional biocatalytic membrane containing laccase-embedded metal-organic frameworks for detection and degradation of phenolic pollutant

In this work, a metal-organic framework material, zeolitic imidazolate framework-90 (ZIF-90), was firstly used to encapsulate laccase (LAC) and to prepare ZIF-90/LAC biocomposites. Afterward, the composites were combined with bacterial cellulose (BC) and carboxylated multi-walled carbon nanotubes (cMWCNTs) by a facile method to achieve a novel cellulose membrane with biocatalytic function, displaying excellent detection and degradation properties towards phenolic pollutant. Notably, the membrane was directly employed as a biosensor electrode, and it exhibited a linear response to catechol from 20 to 400 mu M with a detection limit of 1.86 mu M (S/N = 3), as well as satisfactory selectivity, reproducibility, and stability. In addition, the biocatalytic membrane showed higher degradation efficiency towards catechol than pure LAC, and the catechol degradation efficiency of the membrane generally ranged from 93.4% to 82.1% for five cycles. Moreover, the membrane was successfully applied in enzyme membrane reactor (EMR), achieving satisfactory results. The novel membrane harbors a broad application prospect in the fields of real-time monitor and treatment of phenolic wastewater. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, ZIF-90 was utilized to encapsulate LAC and combine with BC and cMWCNTs to prepare a novel cellulose membrane with biocatalytic function, displaying excellent detection and degradation properties towards phenolic pollutants. The membrane also served as a biosensor electrode with a linear response to catechol and high degradation efficiency and stability.