Engineering pineapple peel cellulose nanofibrils with oxidase-mimic functionalities for antibacterial and fruit preservation

In this study, an antibacterial material (CNF@CoMn-NS) with oxidase-like activity was created using ultrathin cobalt‑manganese nanosheets (CoMn-NS) with a larger specific surface area grown onto pineapple peel cellulose nanofibrils (CNF). The results showed that the CoMn-NS grew well on the CNF, and the obtained CNF@CoMn-NS exhibited good oxidase-like activity. The imidazole salt framework of the CNF@CoMn-NS contained cobalt and manganese in multiple oxidation states, enabling an active redox cycle and generating active oxygen species (ROS) such as singlet molecular oxygen atoms (1O2) and superoxide radical (·O2−), resulting in the significant inactivation of Staphylococcus aureus (74.14%) and Escherichia coli (54.87%). Importantly, the CNF@CoMn-NS did not exhibit cytotoxicity. The CNF@CoMn-NS further self-assembled into a CNF@CoMn-NS paper with flexibility, stability, and antibacterial properties, which can effectively protect the wound of two varieties of pears from decay caused by microorganisms. This study demonstrated the potential of using renewable and degradable CNF as substrate combined with artificial enzymes as a promising approach to creating antibacterial materials for food preservation and even extending to textiles and biomedical applications. •Nanosheets derived from metal-organic frameworks grew on cellulose nanofibrils (CNF).•A CNF with oxidase-like activity (CNF@CoMn-NS) was developed.•CNF@CoMn-NS showed excellent oxidase-like activity and produced 1O2 and ·O2− species.•CNF@CoMn-NS possessed excellent bacteriostatic activities.•CNF@CoMn-NS was self-assembled into a paper for protecting the wound of fruit.