Brassica oleracea mediated green synthesis of iron oxide nanoparticles and evaluation of their biological activities

Abstract In the present study, Fe₂O₃-NPs were successfully synthesized via an environmentally benign green synthesis method using the extract of Brassica oleracea L. var. capitata as a natural reducing and stabilizing agent. The biosynthesized Fe₂O₃-NPs were comprehensively characterized using a range of structural, morphological and spectroscopic techniques to elucidate their physicochemical properties and evaluate their suitability for biomedical applications, including antifungal, antibacterial, antioxidant, anti-inflammatory and anticancer activities. Powder X-ray diffraction (PXRD) analysis confirmed the crystalline nature of the nanoparticles and was employed to determine their crystallographic parameters and average crystallite size, which was found to be in the range of 13–20 nm. Fourier transform infrared (FTIR) spectroscopy was utilized to identify the surface functional groups and phytochemical constituents responsible for reduction and stabilization of the NPs. The surface morphology of Fe₂O₃-NPs was examined using scanning electron microscopy (SEM), whereas their particle size, morphology and microstructural features were further elucidated by transmission electron microscopy (TEM). The optical absorption spectrum of the NPs was investigated using UV–Visible spectroscopy over the wavelength range of 200–800 nm. Furthermore, the synthesized Fe₂O₃-NPs were subjected to comprehensive biological and physicochemical evaluations to assess their multifunctional potential for biomedical and related technological applications.