The plant-based extract can be used to synthesize silver nanoparticles (Ag NPs) as
a reducing agent. In the present study, Oregano leaves’ extracts were extracted using ethanol
to synthesize Ag NPs. The effects of different parameters such as the processing time, temperature,
and stirring rate on the mean particle size, concentration, and zeta potential of the synthesized
Ag NPs solutions were optimized using Response Surface Methodology (RSM). At the optimum
condition, which includes processing time (30.48 min), temperature (70 ºC), and stirring rate
(370.530 RPM), Ag NPs were obtained with 33 nm of the mean particle size, 76.109 ppm of
concentration, and +17.2 mV of zeta-potential. In this condition, Ag NPs displayed high antibacterial
activity against Gram-negative and Gram-positive bacteria. In addition, the maximum antioxidant
activity of 11.7% was obtained at optimum synthesizing conditions