Biocatalytic oxidative coloration of bio-based Nylon 5,10 using natural phenolics

This study explores an eco-friendly, enzyme-mediated oxidative dyeing strategy for the coloration of bio-based Nylon 5,10 using natural phenolic precursors. Horseradish peroxidase (HRP) was employed to induce the oxidative polymerization of catechol and hydroquinone, enabling color development without the use of conventional synthetic dyes or mordants. The fixation pathway of the oxidized phenolic products on the polyamide surface was elucidated using a combination of FT-IR spectroscopy, LC-MS, and SEM, confirming that HRP-generated quinonoid species form chemically bound and surface-anchored polymeric pigments on Nylon 5,10. In addition, antimicrobial evaluation revealed that HRP-polymerized hydroquinone exhibited clear inhibitory activity against both Escherichia coli and Staphylococcus aureus. Furthermore, the dyeing behaviour of Nylon 5,10 was compared with that of conventional Nylon 6 to clarify how structural differences influence enzyme-mediated color fixation. Taken together, this work highlights the potential of coupling a bio-derived fibre platform with a biocatalytic coloration process to advance environmentally responsible and functionally enhanced textile finishing.