Stability of Biosynthesised Silver Nanoparticles Using Achyranthes aspera Roots and Its Characterization

The present investigation was aimed to study the biosynthesis, stability and characterization of silver nanoparticles using Achyranthes aspera root extract. Synthesis of silver nanoparticles has been done by maintaining different AgNO3 concentrations (0.50, 1.00, 1.50 and 1.84 mM), temperature (25, 45, 75, 105 and 125 ºC) and pH conditions (4, 5, 7, 9 and 10). By analysing the data obtained during stability study, it was found that, combination of AgNO3 of 1.15 mM concentration, temperature at 45 ºC and pH of 9 was the best condition to synthesize the stable Ag NPs for one month. Characterization of synthesized silver nanoparticles was done by zetasizer, UV-Vis spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Particle size distribution of zetasizer indicated that the size of the biosynthesized silver nanoparticles was 23.21 nm and UV-Vis spectroscopy showed its absorbance peak at 420 nm, which confirmed the presence of Ag NPs. XRD analysis confirmed that, resultant Ag NPs were face-centered cubic in nature and AFM analysis showed surface area (103.97 µm2), selected particle height (0.12 µm) and width (1.10 µm). It was concluded that, green synthesis was an eco-friendly and most economical way to produce silver nanoparticles over the chemical and physical methods