The in vivo biosynthesis of antibacterial silver nanoparticles using red pepper (Capsicum annuum L) fruit extract

Abstract

Green synthesis of nanoparticles using biological organisms is of increased demand by many scientific and economic sectors. Biosynthesis of silver nanoparticles was undertaken using aqueous extract from red fleshly sweet fruits of Capsicum annuum and the antibacterial activity of silver nanoparticles (Ag NPs) was investigated. We tracked color change of pepper extract from orange to deep dark brown after 10 mins of incubation with silver nitrate (1mM) solution. Silver nanoparticles have been characterized using three techniques: UV-Vis spectrophotometry at 415 nm for detection of characteristic optical absorption band of Ag NPs, FTIR spectroscopy; for information about the water-soluble molecules of red pepper fruit that were responsible for the reduction process, and, the crystalline nature and mean size of Ag NPs were studied using X-ray diffraction according to the line width of the plane and the refraction peak has been calculated using the ScherrerÂ’s equation. Elemental analysis showed the presence of strong peak of silver at 3 KV which confirmed the synthesis of silver element. The biosynthesized Ag NPs possessed moderate antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Aramco S4 bacterial isolate with inhibition zones of 2 to 3 mm.