Green Synthesis of Iron Oxide, and Iron Oxide/ Cerium Oxide Nanoparticles Using Ficus nitida Extract: Antimicrobial and Antioxidant Activities

Abstract

To minimize environmental impact, the green synthesis strategy prioritized using non-toxic substances, energy-efficient processes, and renewable resources. Ficus nitida fruit extract was used to produce Iron oxide nanoparticles (Fe₂O₃ and Fe₃O₄ NPs) and Iron oxide/cerium oxide nanoparticles (Fe₂O₃ and Fe₃O₄/CeO₂ NPs) for antimicrobial, and antioxidant applications. The effective synthesis of these NPs was confirmed by X-ray diffraction (XRD), FTIR, UV-visible, and transmission electron microscopic (TEM) analyses. The typical crystal diameters, as estimated by the Debye–Scherrer equation, were 3.65 nm (Fe₂O₃ and Fe₃O₄ NPs) and 10.14 nm (Fe₂O₃ and Fe₃O₄/CeO₂ NPs). TEM images verified that the prepared NPs were spherical, semispherical, and irregular in shape. The FTIR spectrum's prominent peaks revealed the elements of Fe–Ce nanoparticles. Of all the materials examined, Fe₂O₃ and Fe₃O₄ /CeO₂ NPs synthesized using Ficus nitida fruit extract demonstrated promising in vitro antibacterial activity against MRSA (21.0 ± 0.58 mm inhibition zone) and E. coli (22.2 ± 0.15 mm), alongside antioxidant potential (81.76% free radical scavenging at 1000 µg/mL). These preliminary findings merit further investigation to assess toxicity, biocompatibility, and in vivo efficacy as potential antibacterial and antioxidant agents in advanced applications.