Characterization of silver nanoparticles synthesized from Helianthus annuus leaf extracts and antibacterial potential against foodborne pathogens

The synthesis of nanoparticles using biological substances, such as plants, has proven to be more beneficial, eco-friendly, and cost-effective. This study emphasised the green biogenic synthesis of silver nanoparticles (AgNPs) from Helianthus annuus L. leaf extracts in ethyl acetate (AgNPEa) and methanol (AgNPM), along with antibacterial and antioxidant properties of the resulting nanoparticles. The phytochemical analysis of the ethanol and ethyl acetate extracts was done. Characterization (UV-visible (UV-Vis), Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray diffraction techniques (XRD) and FTIR), antioxidant and antibacterial potential of the synthesised AgNPs were done. The two extracts showed no cardiac glycosides. A change in colour of the silver salt solution, showing a maximum UV-vis absorbance at 450 nm for AgNPMHa and 500 nm for AgNPEaHa. The SEM and TEM revealed a spherical shape having about 26.8 ± 9.4 nm and 22.3 ± 6.8 nm size. The EDX showed a high silver content of 69.35% in AgNPMHa and 72.40% in AgNPEaHa while XRD showed planes of pure silver ions. FTIR analysis the capping and stabilization of nanoparticle. Hydrogen peroxide, reducing power and total antioxidant activity increased dose-dependently (55 ± 23%, 63%, and 57% for AgNPEaHa and 57.03 ± 17%, 69.62 ± 21%, and 56% for AgNPMHa at 400ul) and both susceptible to Escherichia coli. The results confirmed that Helianthus annuus is a potential biomaterial for synthesizing AgNPs which can be exploited for its antioxidant and antibacterial activity.