Biosynthesis and Characterization of Silver Nanoparticles Using Papaya Leaves and Estimation of its Antibacterial Activity

In the present study, we aim in the biological synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Carica papya. Bio reduction of Ag+ to Ag0 was observed when aqueous extract augmented with silver nitrate (AgNO3) and kept at different reaction conditions (temperature, extract concentration). Reducing ability of the leaf extract of Carica papaya in the formation of silver nanoparticles (AgNPs) from silver nitrate was tested by determining the total phenolic content in papaya leaf, which act as reducing and capping agent. The formation of silver nanoparticles was primarily analysed by surface Plasmon resonance as determined by UV-VIS spectra ranging from 420-680 nm. Silver nanoparticles of size ranging 13-17 nm of spherical shape and smooth surface were characterized using transmission electron microscopy (TEM), which is the confirmatory analysis. Particles compositions were studied using FTIR spectroscopy. These nanoparticles were found to possess potential antibacterial activity against Escherichia coli with considerable zone of inhibitions by Oxford agar well diffusion method and turbidimetric measurements. This environmental friendly method provides a simple, easy, fast and cost effective method for nanoparticles synthesis and can be used in several areas of medicines including drug targeted delivery and gene therapy.