Green Synthesis, Characterization, and Antifungal Efficiency of Biogenic Iron Oxide Nanoparticles

Abstract

The high incidence of fungal resistance to commercial fungicides and the negative effects of chemical fungicides on the environment and human health necessitate the development of novel biofungicides for the efficient management of fungal diseases. This study aims to greenly synthesize iron oxide nanoparticles (IONPs) using the aqueous extract of Laurus nobilis leaves and characterize these nanoparticles using various physicochemical techniques. The biogenic IONPs were tested against two pathogenic strains of Alternaria alternata and compared to the metalaxyl–mancozeb fungicide. The food poisoning technique was used to assess the antifungal efficacy of the greenly synthesized IONPs and the commercial metalaxyl–mancozeb fungicide against the tested pathogenic A. alternata strains. The biogenic IONPs showed a higher antifungal efficiency against the A. alternata OR236467 and A. alternata OR236468 strains at concentrations of 800 ppm compared to metalaxyl– mancozeb fungicide, with relative growth inhibition percentages of 75.89 and 60.63%, respectively. The commercial metalaxyl–mancozeb fungicide (800 ppm) showed growth inhibition percentages of 72.23 and 58.54% against the same strains. The biogenic IONPs also showed potential antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, with DPPH inhibition percentages of 34.61% to 83.27%. In conclusion, the biogenic IONPs derived from L. nobilis leaves have the potential to be employed as biofungicides for the effective control of fungal phytopathogens, reducing reliance on harmful chemical fungicides.