Preparation, characterization and antifungal activity of iron oxide nanoparticles

Iron oxide nanoparticles with particle size 10-30 nm were prepared by a green approach using tannic acid as reducing and capping agent. These nanoparticles were characterized by X-ray diffractometry (XRD), high resolution field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The prepared iron oxide nanoparticles were also evaluated for their antifungal activity against Trichothecium roseum, Cladosporium herbarum, Penicillium chrysogenum, Alternaria alternata and Aspergillus niger. The antifungal activity was observed as inhibition in spore germination and by determining the zone of inhibition of fungal pathogens caused by different concentrations of iron oxide nanoparticles on culture media. It was observed from the present study that Fe₂O₃ nanoparticles showed significant antimycotic activity against all the tested fungal pathogens. Highest inhibition in spore germination was caused against T. roseum (87.74%) followed by C. herbarum (84.89%). The highest zone of inhibition by iron oxide nanoparticles was reported against P. chrysogenum (28.67 mm) followed by A. niger (26.33 mm), T. roseum (22.67 mm), A. alternata (21.33 mm) and least against C. herbarum (18.00 mm). Activity index was recorded highest against P. chrysogenum (0.81). The MIC value of Fe₂O₃ NP varies between 0.063 and 0.016 mg/ml for different fungal pathogens that is comparable with the MIC value shown by the standard, revealing the efficacy of iron oxide NP's against different fungal pathogens.