Effect of Green Synthesized of Graphene-Ag Nano-Composites on the phytochemistry of Stevia Rebaudiana

Many methods have been used to progress production of medicinal natural products. With the progress in nanotechnology, nanoparticles have been recorded to have variable effect in plant growth and inducibility of phytochemical composition. Major impartial of the study was to study the secondary metabolite modulatory effect of synthesized silver nanoparticles and graphene/silver nano-composites. Bio-applications of graphene/nanoparticle hybrid materials in several studies have used. In this study, we exhibit a new, simple, low cost, environmentally safe process for the biosynthesis of graphene/silver nano-composites using stevia plant extract. Stevia rebaudiana Bertoni, a plant originating in Paraguay, produces a variation of high-potency, low calorie sweeteners in its leaf tissue. After synthesis of Ag nanoparticles by treatment of an aqueous solution of AgNO3 with stevia plant extract, graphene was added to the synthesized nanoparticle solution and sonicated in the ultra-sonication bath. The synthesized nano-composites were characterized by UV-visible spectroscopy, transmission electron microscopy. The essential oil composition of the aerial parts of Stevia rebaudiana cultivated in Sana Institute (Iran) were studied by GC and GC/MS. Plant treated with GN/Ag nano-composites showed higher content of caryophyllene oxide (4.3-17.7%), spathulenol (15.3-51.9%), β-pinene (6.5-24.3%), and β-caryophyllene (3.12-18.0%) respectively, than individual nanoparticles, graphene alone, plant without treatment of nanoparticles. Current results show that GN/Ag nano-composites can be eco-friendly synthesized using stevia leaf extract. The graphene/metal nano-composites produced may be less-toxic, biocompatible, and useful for bio-applications. Hence the study is of giant application as it opens up advance of new methods based on nanoelicitors to improve the biosynthesis of medicinal natural products in plants [1, 2].

Keywords:

Graphene , synthesized Ag nanoparticle , Nanocomposites , Stevia Rebaudiana.