GREEN SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM AQUEOUS EXTRACT OF BASELLA ALBA AND THEIR IN-VITRO ANTIOXIDANT POTENTIALS

Objective: To synthesize silver nanoparticles (AgNps) from Basella alba(B. alba) aqueous extract using 3 mM AgNO3 solution, to characterize the resulted AgNps and also to study the antioxidant activity by DPPH and reducing assay. Methods: 150 ml of aqueous extract was mixed with 600 ml of 3 mM silver nitrate solutions and kept at room temperature for 1hr. A change from straw yellow to golden yellow was observed and absorption spectra were obtained by UV-VIS spectrometer. The resulted nanoparticles (NPs) were characterized by FT-IR spectrum, SEM-EDS, TEM and XPS techniques. The purity and nature of the particles were observed through TG-DSC analysis. Further, Antioxidant activity was performed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) method and by Ferric chloride reducing assay. Results: UV-Vis spectral analysis shows a maximum absorption peak at 435 nm. FT-IR spectrum indicated the formation of reducing and capping agents in AgNps. The synthesized silver nanoparticles was spherical in shape and its size ranges from 22.6 to 25 nm. The synthesized silver nanoparticles possess excellent antioxidant activity by various methods. The phenol carboxylic acid present in B. alba leaf extract acted as a reducing agent which was identified by HPTLC technique. A Protein present in the B. alba extract was responsible for the capping of bio-reduced silver nanoparticles. Conclusion: It has been demonstrated that Basella alba plant extract could be used as a proficient green reducing agent for the synthesis of AgNPs. Further studies will be focused towards the mass scale production of formulation