Synergistic Antioxidant and Antimicrobial Efficacy of Novel Ag/Fe3O4 and S/Fe3O4 Nanohybrids Orchestrated by Brassica napus Phytochemicals

• Hisham T. Hameed1, *Sirhan. M.M2

  Author

       This study presents a simple green synthesis of Fe₃O₄-NPs and their nanohybrids (Ag/ Fe₃O₄and S/ Fe₃O₄) with the aid of Brassica napus leaf extract acting as a bioreducing and capping agent. The stabilization of the nanoparticles by the presence of plant phytoconstituents, especially phenolics, flavonoids and proteins, was determined using FTIR spectroscopy. The XRD analysis confirmed the presence of phase-pure magnetite NPs that crystalize in a cubic spinel structure with an average particle size of about 6.26 nm. TEM analysis showed quasi-spherical-shaped Fe₃O₄ NPs with an average particle size of ~7.5 nm with a narrow size distribution, whereas the FESEM studies showed particle sizes to be ~10.7 nm, which further increased to ~16.7 nm and ~19.18 nm for Ag/Fe₃O₄ and S/Fe₃O₄, respectively, thus validating the successful synthesis of nanohybrids and modification of Fe₃O₄ NPs surfaces. Evaluation of the biological activity was carried out using antioxidant (DPPH) and antibacterial assays. Ag/Fe₃O₄ NPs displayed significant enhancement in antioxidant activity (88.32% scavenging ability, IC₅₀ value = 199.10 µmol/L) compared to Fe₃O₄ (IC₅₀ value = 422.12 µmol/L) and S/Fe₃O₄ NPs (IC₅₀ value = 420.11 µmol/L), respectively, due to a synergistic effect. The antibacterial assay demonstrated that Ag/Fe₃O₄ NPs are more effective, with an inhibition zone of 18 mm and 19 mm with E. coli and S. aureus, respectively, as compared to other samples. The high surface reactivity, potential of electron transfer and synergistic effect of the physicochemical properties of the nanohybrids make them highly active. These results clearly show that green synthesized Ag/Fe₃O₄ nanohybrids are an excellent candidate for a variety of multifunctional platforms with sophisticated biomedical and antimicrobial uses.

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