This study demonstrates the biosynthesis and characterization of silver nanoparticles (AgNPs) using aqueous and alcoholic extracts of turmeric (Curcuma longa). The synthesized AgNPs entailed characterization by UV-Vis spectroscopy, atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR). The UV-Vis analysis revealed absorption peaks between 300 and 520 nm, confirming nanoparticle AFM indicated nanoparticle size ranges of 0–23 nm for the alcoholic extract and 1–10 nm for the aqueous extract. The FTIR analysis identified the compounds responsible for reducing the silver nitrate. The antifungal activity measurement of the synthesized AgNPs ensued against three phytopathogenic fungi: Alternaria alternata, Alternaria dianthi, and Fusarium verticillioides. The results demonstrated silver nanoparticles effectively inhibited fungal growth, with an inhibition zone diameter of 52.4 mm in A. alternata, 52.0 cm in A. dianthi, and 41.5 mm in F. verticillioides. Treatment with biosynthesized AgNPs also resulted in reduced fungal biomass and elevated pH levels in the culture medium. The effectiveness of bio-silver nanoparticles against A. alternata, A. dianthi, and F. verticillioides fungi succeeded in testing at different concentrations. It further showed the highest inhibitory concentration (20 ppm) for all the fungi, averaging over colony diameters (3.1, 3.9, and 1.5 cm, respectively) for nanoparticles of the aqueous extract and fungal colony diameters (2.3, 3.1, and 2.2 cm) in the alcoholic extract.
Silver nanoparticles, aqueous and alcoholic turmeric extracts, antifungal activity, fungal biomass, pH level, UV-Vis, FTIR, AFM
Silver nanoparticles produced from turmeric plant extracts proved to be a safe antifungal substance and highly effective in inhibiting the growth of fungi A. alternata, A. dianthi, and F. verticillioides.