Ultrasimple Preparation of Visible Light Photocatalytic Antibacterial Superparamagnetic Iron Oxide Nanoparticles and Their Antibacterial Mechanisms Study

Bacterial infections are major challenges in global public health currently, it is particularly important to develop novel, efficient and environment-friendly antibacterial methods. In this study, PEG and PEI co-modified superparamagnetic iron oxide nanoparticles (PEG/PEI-SPIONs) with high crystallinity were prepared by ultra-simple high-temperature thermal decomposition reaction. Modification with PEG and PEI enhanced the water solubility and stability of the SPIONs. The experimental results showed that PEG/PEI-SPIONs exhibited good photocatalytic inhibitory effects against S. aureus and E. coli, and a dose-dependent antibacterial activity. The antibacterial activity of PEG/PEI-SPIONs were significantly enhanced under xenon lamp irradiation. The main antibacterial mechanisms of PEG/PEI-SPIONs primarily involve biofilm inhibition and destruction, and inducing the production of reactive oxygen species, resulting in the death of the bacteria. The PEG/PEI-SPIONs constructed in this study are expected to replace antibiotics in the fight against bacterial infections.