Laccase immobilized on amino acid ionic liquid-modified magnetic lignin nanoparticles and its degradation of...

Immobilized laccase demonstrates significant potential for 2,4-dichlorophenol (2,4-DCP) degradation in environmental remediation applications. However, challenges persist in optimizing carrier materials for enzyme immobilization. In this study, a magnetic lignin-based nanocomposite (Fe₃O₄-SL) was synthesized and further functionalized with amino acid-derived ionic liquids (AAILs). Laccase was immobilized onto the modified nanoparticles to obtain the biocatalyst Lac-AAIL⁺-PF6^-, whose stability and catalytic performance were systematically evaluated. Compared to free laccase, Lac-AAIL⁺-PF₆^- exhibited superior thermal stability and resistance to denaturing agents. When applied to 2,4-DCP degradation, the immobilized laccase achieved a degradation efficiency exceeding 95 % under optimized conditions. Notably, the biocatalyst retained over 60 % degradation capacity after five consecutive reaction cycles, demonstrating remarkable reusability. This work successfully engineered a lignin-supported AAIL-modified magnetic carrier, offering a novel strategy to enhance immobilized laccase performance for sustainable wastewater treatment.