Biogenic synthesis and characterization of iron oxide (α-Fe2O3) nanoparticles using Microcos paniculata L. bark extract and its bio-medical applications

Green manufacturing of nanoparticles (NPs) is an eco-beneficial and safer approach as presented in this work. Nanoparticles will be synthesized without utilizing hazardous chemicals by using bark extract as a source of reducing agents. Herein, iron oxide nanoparticles (α-Fe 2 O 3 NPs) were synthesized utilizing an aqueous bark extract of Micrococcus paniculata L. Further characterization of the α-Fe 2 O 3 NPs was performed by an ultraviolet-visible (UV-Vis) spectrometer, which showed a clearly visible peak at 290 nm. X-ray diffraction (XRD) was utilized to establish the crystallinity of the produced NPs. The crystalline size of the synthesised α-Fe 2 O 3 NPs was 24 nm, and the XRD analysis confirmed their presence in the purest crystalline form. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of Fe–O stretching vibrations associated with iron oxide nanoparticles. The research carried out by means of energy-dispersive X-ray (EDX) and transmission electron microscopy (TEM) demonstrated 74 nm average-sized nanoparticles with quasi-spherical and irregular morphology. Biogenically synthesized α-Fe 2 O 3 NPs showed antifungal efficacy against fungal pathogens, i.e., Candida albicans NCIM 3466 and Aspergillus niger NCIM 773. The α-Fe 2 O 3 NPs showed a prominent antifungal efficacy against the growth of Aspergillus niger (23 mm inhibition at 100 µg/mL) and Candida albicans (26 mm inhibition at 100 µg/mL). The α-Fe 2 O 3 NPs showed the scavenging activity of 81.23 ± 0.65% at the highest concentration (100 µg/mL) tested with standard ascorbic acid as a positive control. The results indicated that the prepared α-Fe 2 O 3 NPs can be used for the treatment of antifungal infections and also as an antioxidant medicine.