Biosynthesis and Optimization of AgNPs Yield from Chromolaena Odorata Leaf Extract Using Response Surface Methodology (RSM)

Using plant bioresources to produce nanoparticles has emerged as a low-cost, eco-friendly process and an ethically sound way of protecting and preventing the environment from releasing toxic and hazardous substances associated with other synthetic methods. In this study, silver nanoparticles were prepared by using Chromolaena odorata leaf extract bio-reduction of silver nitrate. The bio-reduced nanoparticles were characterized by UV-Vis, FTIR, and SEM coupled with EDS. The effects of the volume ratio of plant extract to silver nitrate solution, time, and concentration were examined on the yields of the nanoparticles using a central composite factorial design and a response surface model. The FTIR spectrum of the synthesized silver nanoparticles showed the possible involvement of conjugated C-C and C-O-H groups in the bio-reduction process. The nanoparticles showed some antimicrobial properties against some tested pathogens. The nanoparticles appeared clustered and aggregated together in morphology. The optimum nanoparticle yields were obtained using low values of the ratio of plant extract to silver nitrate solution (1:1) and high values of time (45 minutes) and concentration of silver nitrate (3 mM), respectively. These are possible reaction conditions for maximizing nanoparticle yields from Chromolaena odorata leaves.