White-light driven sterilization based on chlorine-doped cuprous oxide for antibacterial food packaging

Abstract

Microbial spoilage and pathogen contamination present significant challenges to food quality and safety. Incorporating photodynamic sterilization (PDT) into active packaging films, especially using white light-driven methods, is recognized as one of the most effective strategies to combat microbial contamination and extend shelf-life. Cuprous oxide (Cu2O) shows promise due to its suitable band gap for absorbing visible light, although its photocatalytic effectiveness is hindered by electron-hole recombination. In this study, a chlorine (Cl) doping strategy was investigated to enhance Cu2O’s PDT capabilities under visible light. This approach aimed to improve Cu2O’s band structure for generating reactive oxygen species (ROS) and to enhance charge carrier separation efficiency, thereby inhibiting recombination. The resulting Cl-doped Cu2O (Cl-Cu2O) exhibited enhanced antibacterial activity, which was integrated into a gelatin (Gel) and carboxymethylcellulose (CMC)-based food packaging film, referred to as the GC/Cl-Cu2O film. This innovative film provides a white light-driven active packaging solution designed to extend the shelf life of fruits by suppressing microbial growth. This approach not only addresses food safety concerns but also mitigates economic losses associated with food waste, offering a sustainable solution to enhance the quality and safety of perishable goods.