Cellulase immobilization via surface-grafted block copolymers on polypropylene fibers

Biomass resources represent a sustainable alternative to fossil-based feedstocks for energy and value-added chemical production, and their utilization hinges largely on cellulase-catalyzed glucose conversion. Various immobilization strategies have been developed with the aim of cellulase recyclability. However, these strategies suffer from inadequate interactions between the substrate and immobilized cellulases, as well as poor recyclability. To overcome these drawbacks, we developed a hierarchical polymer brush architecture on polypropylene fibers through sequential photoinduced grafting and surface-initiated atomic transfer radical polymerization. This platform features hydrophilic polymer segments followed by reactive epoxy-functionalized brushes for covalent cellulase immobilization, enhancing substrate-enzyme interactions and cellulase stability against environmental alternations (especially harsh conditions). Importantly, the immobilized biocatalyst maintained 60% initial activity through six cycles in sodium carboxymethyl cellulose hydrolysis. This fiber-grafted block copolymer platform demonstrates an efficient strategy for cellulase immobilization, which opens up a new avenue for high-performance enzyme immobilization in industrial biocatalysis. Graphical abstract