Flower like ZnO hybrid mediated visible light harvesting film with upgraded photodynamic antibacterial capacity for effective food preservation

Abstract

Active food packaging film with light-driven antibacterial properties has inspired numerous interests for food preservation, while efficiently retains the photocatalytic ability remains highly challenging. This study pioneered an advanced visible light-driven photodynamic antibacterial packaging film (FZ-PC) employing an organic-inorganic hybrid strategy, meticulously engineering flower-like zinc oxide functional fillers (FZnO) with superior photoactivity and subsequently formulating a polyvinyl alcohol/sodium carboxymethyl cellulose (PC) mixed film matrix to enhance its physical and chemical properties. The boosting photodynamic activity of the FZnO results from the molecular-level optimization through citral modification. Collectively, the robust electrostatic interactions with bacteria and the enhanced generation capabilities of ¹O₂, •O₂⁻, and •OH equip the FZ-PC film with superior bacterial inactivation properties, which can reduce the concentrations of Salmonella enteritidis and Staphylococcus aureus by 6 and 6.3 log, respectively. Furthermore, the FZnO-PC film showed lower UV transmittance, higher water contact angle and better mechanical strength. The enhanced antibacterial behavior and improved physicochemical properties of the composite film render it an ideal solution for fruit and vegetable preservation, significantly extending the storage life of cherry tomatoes from 4 days to 11 days. These findings suggest that the developed FZnO-PC film represents a promising advancement in packaging technology.