Antimicrobial potential of green synthesized CeO₂ nanoparticles from Olea europaea leaf extract

This article reports the green fabrication of cerium oxide nanoparticles (CeO₂ NPs) using Olea europaea leaf extract and their applications as effective antimicrobial agents. O. europaea leaf extract functions as a chelating agent for reduction of cerium nitrate. The resulting CeO₂ NPs exhibit pure single-face cubic structure, which is examined by X-ray diffraction, with a uniform spherical shape and a mean size 24 nm observed through scanning electron microscopy and transmission electron microscopy. Ultraviolet-visible spectroscopy confirms the characteristic absorption peak of CeO₂ NPs at 315 nm. Fourier transform infrared spectroscopy reflects stretching frequencies at 459 cm^-1, showing utilization of natural components for the production of NPs. Thermal gravimetric analysis predicts the successful capping of CeO₂ NPs by bioactive molecules present in the plant extract. The antimicrobial studies show significant zone of inhibition against bacterial and fungal strains. The higher activities shown by the green synthesized NPs than the plant extract lead to the conclusion that they can be effectively used in biomedical application. Furthermore, reduction of cerium salt by plant extract will reduce environmental impact over chemical synthesis.