Green Synthesis of Crystalline Silver Nanoparticles Using Pomegranate Peel Extract: Structural Characterization and Light-Enhanced Antibacterial Activity Against Foodborne Pathogens

Abstract This work offers a sustainable and environmentally friendly way to create silver nanoparticles (AgNPs) by employing pomegranate peel extract (PPE) as a natural stabilizing and reducing agent. When silver nitrate was added, the color changed visibly from pale yellow to dark orange, indicating the reduction of silver ions and the creation of PPEAgNPs. The produced nanoparticles were found to be semi-spherical, crystalline, and of high purity using characterization techniques such as Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). They also had distinct diffraction peaks that corresponded to the (111), (200), (220), (311), and (222) lattice planes. According to antibacterial tests, PPE-AgNPs have a strong inhibitory effect on Salmonella typhimurium, Listeria monocytogenes, and Staphylococcus aureus, three important food-borne and clinical pathogens. The most noticeable inhibitory zones were seen at higher doses (10 mM), indicating that the antibacterial activity was dose-dependent. Furthermore, it was shown that exposure to light increased the antibacterial efficiency of PPE-AgNPs. This is probably because photoactivation processes boost the generation of reactive oxygen species (ROS), which in turn enhances the breakdown of bacterial membranes. These results support the use of agro-waste-based nanotechnology in the environmental and biomedical fields and highlight the potential of PPE-AgNPs as powerful, light-responsive antibacterial agents.