In-situ encapsulation and construction of Lac@HOFs/hydrogel composite for enhancing laccase stability and azo dyes decolorization efficiency

• Published in: Carbohydrate polymers 2023-11, Vol.320, p.121157-121157, Article 121157
• Main Authors: Yang, Xue, Shi, Fei, Su, Xiaolei, Cavaco-Paulo, Artur, Wang, Hongbo, Su, Jing
• Format: Article
• Language: English
• Subjects: Hydrogel composite; Hydrogen-bonded organic framework; Laccase immobilization; Water remediation
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2023.121157

Enzymes with high catalytic activity and stability have been used for the sustainable development of green chemical applications, such as water remediation. Immobilized laccase can be used to construct a synergistic system for adsorption and degradation, which has great potential for water remediation. Herein, a hydrogen-bonded organic framework was installed onto laccase in-situ to form a net-carboxylate-arranged defective cage, which enhanced its catalytic stability. Thereafter, the CMC/PVA/Lac@HOF-101 hydrogel was fabricated by freeze–thaw cycles using sodium carboxymethylcellulose and polyvinyl alcohol as carriers and copper (II) as a cross-linker. Notably, the MOFs/hydrogel as a protective carrier of laccase maintain long-term recyclability and catalytic stability. After the fifth catalytic cycle, approximately 66.7 % activity of the CP-Lac@HOF-101 was retained. When both free laccase and CP-Lac@HOF-101 were used for decolorization of Acid Orange 7 (AO), the removal rates were 10.9 % and 82.5 % after 5 h, respectively. Furthermore, even in the presence of metal cations, almost 60.0 % of the AO removal efficiency was achieved. The relationship between the structure of the azo dyes and decolorization efficiency of the synergistic system was further investigated. This study offers a method for constructing enzyme@HOF-based composite hydrogels and provides a promising water remediation strategy. [Display omitted]