This research investigated the antibacterial activities of AgFe2O4 and Fe3O4 ferrite nanoparticles compared to AgFe2O4/SiO2/Passiflora Caerulea and Fe3O4/SiO2/Passiflora Caerulea nanocomposites. To synthesize ferrite nanocomposites, Passiflora Caerulea plant extract was doped onto ferrite nanoparticles with the assistance of silica (SiO2). The degree of crystallinity, phase composition, microstructure, and the compositions of the samples were determined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray analysis (EDXA), respectively. Furthermore, the broth microdilution method was employed against Gram-positive and Gram-negative bacteria to assess the antimicrobial activity. The method was also applied to Gram-positive and Gram-negative bacteria to examine the antimicrobial activity. The results of the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of silver and iron nanocomposites indicated that these nanocomposites exhibited superior antibacterial activity compared to silver and iron ferrite nanoparticles. Thus, silver and iron ferrite nanocomposites could serve as a novel antibacterial agent against infectious bacteria.