Photocatalytic Ag-MOF confers efficient antimicrobial activity to modified polyvinyl alcohol films

Antimicrobial packaging films are an effective means to avoid food infections. PVA has good film-forming and mechanical properties, but its water resistance and antimicrobial properties are insufficient. In this study, a rod-shaped Ag-MOF with photocatalytic properties was synthesized as an antimicrobial agent by a hydrothermal method using citrate esterified PVA as a film-forming substrate. The MICs of Ag-MOF against Escherichia coli and Staphylococcus aureus were 16 μg/mL and 32 μg/mL, respectively, and it had good biocompatibility. Under blue light irradiation, Ag-MOF induced the production of ROS, which increased the inhibition rate by more than 83.78%. The antimicrobial mechanism experiments showed that it caused irreversible damage to the bacterial cell membrane through the synergistic effect of Ag + and ROS. The best mechanical properties of the films were obtained at 3% citric acid content, with the water vapor transmission rate, water solubility and swelling rate reduced by 0.19 g·mm·m −2 ·h −1 ·kPa −1 , 65.33% and 11.26%, respectively. The antimicrobial rate of the composite film could reach more than 98% by adding only 1 MIC of Ag-MOF. In conclusion, photocatalytic antimicrobial agents have great potential for application in food packaging.