Green synthesis of FeO nanoparticles from coffee and its application for antibacterial, antifungal, and anti-oxidation activity

This study presents a sustainable method for producing iron oxide nanoparticles (FeO NPs) using aqueous extracts from coffee seeds. Characterization through X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM) revealed non-spherical NPs ranging from 30 to 50 nm. The XRD analysis confirmed that the face-centred cubic structure and the Debye–Scherrer’s crystalline size support the FeO particle size confirmed from TEM. The synthesized NPs demonstrated significant antimicrobial activity against Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Aspergillus niger. Additionally, they exhibited potent antioxidant properties, effectively inhibiting DPPH, α-amylase, and α-glucosidase compared to acarbose and coffee extract. The findings suggest that these FeO NPs hold promise as antimicrobial, antioxidant, antifungal, and potentially antidiabetic agents.