Green synthesis of silver nanoparticles using Salvia fruticosa Mill. extract and the effect of synthesis parameters on their formation, antioxidant, and electro-catalytic activity

Among green synthesis methods, which are an eco-friendly, non-toxic, simple, and safe approach for the synthesis of silver nanoparticles (AgNPs), using plant extract is the most efficient method. Salvia fruticosa Mill. which was not used formerly was selected for this research. By changing the synthesis parameters (the amount of extract, extract concentration, and silver ion concentration in precursors), their effects on the formation and structure of nanoparticles were investigated by UV-visible spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy techniques. The antioxidant activity of extracts and AgNPs was evaluated by performing DPPH assay. It is observed that the phytosynthesized nanoparticles also possess antioxidant potentials. Finally, AgNPs were used as modifiers for carbon paste electrode (CPE) and their effect on charge transfer resistance and the ascorbic acid signal was investigated by using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square wave voltammetry (SWV). E1-1/CPE showed good electro-catalytic oxidation of ascorbic acid and can be utilized for the development of the new sensors. According to results, in the process of green synthesis of AgNPs, synthesis parameters are vital as they change not only the size and size distribution of the AgNPs but also their antioxidant activity and electrochemical properties.