Sustainable Functionalization of Cotton Textiles via Enzymatic Modification of Zein with Chitosan: Imparting Durable Hydrophobicity and Antimicrobial Activity

In the textile industry, replacing traditional chemical finishing agents with green and durable processes to develop multifunctional textiles has become an important direction for industry transformation and upgrading. This shift relies primarily on biotechnology, new materials, and clean production processes, aiming to reduce environmental pollution, lower energy consumption, and endow textiles with superior performance. In this study, chitosan (CS) was utilized to modify zein through laccase-mediated glycosylation, thereby the functionalizing cotton fabric with durable hydrophobicity and antibacterial activity. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the successful grafting of CS onto zein. The structural characteristics of glycosylated zein were characterized by Fourier transform infrared (FTIR), 1H nuclear magnetic resonance spectrum (1H NMR), and ultraviolet–visible (UV–Vis) spectroscopy. The functionalized cotton fabric exhibited significant hydrophobicity, achieving a water contact angle (WCA) value of 138.54 ± 2.58°, which remained stable at 111.47 ± 2.45° even after four soaping cycles, demonstrating excellent durability. Further characterization via FTIR, scanning electron microscopy (SEM), and nanomechanical analysis revealed that glycosylated zein formed a dense, rough surface layer on the cotton fabric, contributing to its enhanced hydrophobic properties. Additionally, the functionalized fabric displayed remarkable antibacterial activity with inhibition rates of 98.29% against Escherichia coli and 99.98% against Staphylococcus aureus. Importantly, the treated fabric maintained favorable mechanical properties, air permeability, and water vapor permeability, ensuring its practical applicability. Thereby, this study provided an efficient and eco-friendly strategy for the development of multifunctional cotton textiles.