Amino acid-mediated enzymatic grafting of ferulic acid for enhanced dyeing and functional performance of cotton fabrics

The traditional dyeing and finishing of cotton textiles are plagued by high energy consumption and heavy pollution from synthetic dyes and metal mordants. To address these challenges, this study presents a cleaner production strategy that integrates bio-based amino acid modification with horseradish peroxidase (HRP)/H 2 O 2 catalysis for the sustainable functionalization and dyeing of cotton fabrics. Cotton fabric was sequentially oxidized to introduce reactive carboxyl groups, followed by the covalent grafting of L -lysine or L -tyrosine under mild conditions. Subsequently, ferulic acid (FA), a natural phenolic compound, was grafted onto the modified fabrics via an HRP-mediated enzymatic system.The optimized process, operating at neutral pH and low temperatures, yielded high color strength (K/S) values of 9.52 and 9.02 for lysine- and tyrosine-modified fabrics, respectively. The resulting textiles exhibited superior color fastness (washing grade 4–5, rubbing grade 5), outstanding UV protection (UPF 50 +), and near-complete antibacterial activity (about 100% against E. coli and S. aureus ). MALDI-TOF-MS analysis confirmed the formation of stable covalent bonds through radical coupling and Michael addition, ensuring the durability of the functional finish. This work provides a resource-efficient and eco-friendly alternative to conventional chemical dyeing, reducing the consumption of inorganic salts and alkaline agents typically required in traditional cotton dyeing, contributing to the development of sustainable manufacturing in the textile industry.