Green synthesis of silver nanoparticles using flower extracts of Aerva lanata and their biomedical applications

In the present study, green synthesis of silver nanoparticles (AgNPs) was performed using flower extracts of Aerva lanata (Al) from Amaranthaceae family. The size, shape, and elemental composition of the silver nanoparticles (AgNPs) was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and UV-visible spectroscopy. The dynamic light scattering (DLS), of silver nanoparticles (AgNPs) exhibited mean size of 7.6 nm in the range of 5-15 nm, having a poly-dispersed indexed value of 0.419. Zeta potential contributing to the stability of silver nanoparticles was recorded as -18.7 mV. Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis confirmed the presence of the synthesized AgNPs with an average size range 7 +/- 3 nm. The biosynthesized silver nanoparticles displayed antibacterial activity against Gram-positive and Gram-negative bacteria. The 2,2'-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay revealed antioxidant potential of silver nanoparticles in the concentration of 100 mu g/ml. The photocatalytic activity of silver nanoparticles was evaluated using decolourization of the dyes under the sunlight using UV-Vis. spectroscopy. The results suggest that biosynthesized silver nanoparticles from A. lanata (Al-AgNPs) flower extracts have broad spectrum antibacterial, antioxidant and catalytic activities may be useful in a variety of biomedical and industrial applications.