Biosynthesis of silver nanoparticles using Dittrichia graveolens (Asteraceae) leaves extract: characterisation and assessment of their antioxidant activity

Nanotechnology has gained great interest recently due to its common applications. Synthesis of silver nanoparticles employing medicinal plants is eco-friendly, low cost, and easy. Silver nanoparticles (i-AgNPs) were synthesized using Dittrichia graveolens leaves extract. The structure of i-AgNPs was identified by extensive spectroscopic studies. The antioxidant effect of extract and i-AgNPs was determined by DPPH•, ABTS•+, and FRAP assays. FTIR spectroscopic study displayed the characteristic vibration of the hydroxyl group at 3262 cm-1. Ultraviolet-Visible (UV-Vis) spectrophotometer exhibited the maximum absorption of i-AgNPs at 451 nm. The particle size of the green synthesized nanostructure was determined as 30.7 nm by scanning electron microscope (SEM). The crystal structure of nanoparticles was established as face-centered cubic (fcc) by X-Ray Diffraction (XRD). DPPH activity of i-AgNPs (13.4±0.34 µg/mL, IC50) was found higher than that of the extract (15.4±0.17 µg/mL, IC50). Dittrichia graveolens contains the bioactive compounds that bring out its reducing and stabilizing properties. The extract and i-AgNPs displayed the promising antioxidant effect that may be a raw material for food and pharmaceutical applications.