Magnetic enhancement of Fe3O4 nanoparticles through dual surface modification against biofilm formation

Biofilm formation enhances bacterial resistance, posing major challenges in infection control. This study developed biocompatible magnetite (Fe₃O₄) nanoparticles with improved antibiofilm activity. Fe₃O₄ nanoparticles were synthesized via a hydrothermal method and functionalized with gum Arabic (GA) and folic acid (FA). XRD confirmed a pure cubic spinel structure, while FTIR verified successful surface modification. FESEM revealed quasi-spherical, well-dispersed particles, and UV–Vis analysis showed slight shifts in optical absorption after functionalization. VSM results indicated soft magnetic behavior, with increased saturation magnetization in FA-coated samples and a slight reduction in GA-coated ones. Hemolysis assays confirmed good biocompatibility (<5% hemolysis at 100–400 µg/mL). In combination with H₂O₂, FA-coated Fe₃O₄ nanozymes exhibited the highest inhibitory effect against Pseudomonas aeruginosa and Staphylococcus aureus biofilms. These findings demonstrate that surface functionalization effectively enhances the magnetic, catalytic, and antibiofilm properties of Fe₃O₄ nanoparticles.