Modifying Fe₃O₄-functionalized nanoparticles with N -halamine and their magnetic/antibacterial properties

Magnetic/antibacterial bifunctional nanoparticles were fabricated through the immobilization of antibacterial N-halamine on silica-coated Fe ₃O₄-decorated poly(styrene-co-acrylate acid) (PSA) nanoparticles. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The N-halamine was developed from the precursor 5,5-dimethylhydantoin (DMH) by chlorination treatment, and experimental results showed that the loading amount of DMH on the silica-coated Fe₃O₄-decorated poly(styrene-co-acrylate acid) nanoparticles was adjustable. The as-synthesized nanoparticles exhibited superparamagnetic behavior and had a saturation magnetization of 18.93 emu g^-1. Antibacterial tests showed that the resultant nanoparticles displayed enhanced antibacterial activity against both Gram-positive and Gram-negative bacteria compared with their bulk counterparts.