Enhancing the enzymatic coloration stability of cotton and silk fabrics via polyethylene glycol templates

Enzymatic coloration offers an eco-friendly alternative to synthetic dyeing but faces commercial limitations, including poor reproducibility, low colour fastness and restricted colour range. This study investigated horseradish peroxidase-catalysed oxidation and coloration of four phenolic compounds on silk and cotton fabrics, incorporating polyethylene glycol (PEG) templates to improve dye uptake and stability. Dyeing performance was evaluated using colorimetric analysis, with maximum K/S values reaching 11.6 for cotton and 19.2 for silk (with PEG), representing an improvement of 36.5% and 9.7%, respectively, compared with non-templated samples. Colour fastness to washing, rubbing and light was assessed according to ISO standards, showing that PEG-treated fabrics exhibited ratings that were generally one to two grades higher, or at least equivalent, compared with non-templated samples. Structural and morphological changes were examined by Fourier Transform–infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis, while liquid chromatography–tandem mass spectrometry elucidated the polymerisation mechanism of the oxidised phenolic dyes. These results demonstrate that PEG-templated enzymatic coloration can enhance colour intensity and fastness while maintaining sustainability, providing a viable pathway towards greener textile processing.