a SciTechnol journal Research Article Muchanyereyi et al., J Nanomater Mol Nanotechnol 2017, 6:3 DOI: 10.4172/2324-8777.1000224 International Publisher of Science, Technology and Medicine All articles published in Journal of Nanomaterials & Molecular Nanotechnology are the property of SciTechnol, and is protected by copyright laws. Copyright © 2017, SciTechnol, All Rights Reserved. Journal of Nanomaterials & Molecular Nanotechnology Green Synthesis of Silver Nanoparticles Using Euphorbia Coninalis Stem Extract, Characterization and Evaluation of Antimicrobial Activity Netai Mukaratirwa-Muchanyereyi 1 , Tinotenda Muchenje 1 , Stephen Nyoni 1,2 *, Munyaradzi Shumba 3 , Mathew Mupa 1 , Luke Gwatidzo 1 and Ateek Rahman 1 Abstract Silver nanoparticles were synthesized using Euphorbia Coninalis stem extract which is an eco-friendly and cost effective method compared to other synthesis protocols like chemical and physical methods. Euphorbia Coninalis which is used traditionally for thera- peutic uses was responsible for capping and reducing silver ions to silver nanoparticles. Silver was of a particular interest for this process due to its evocative physical and chemical properties. The silver nanoparticles synthesized were quantiied and characterized using visual examination of the color changes, UV-Visible spectros- copy and Fourier Transform Infrared spectroscopy. The antimicro- bial activity of the synthesized nanoparticles was done by agar disc diffusion method tested against Escherichia coli (Gram-Negative) and Staphylococcus aureus (Gram-Positive). The synthesis of silver nanoparticles was conirmed by color change of AgNO 3 to reddish brown upon addition of the Euphorbia Coninalis stem extract. The UV-Vis spectrum showed broad absorption band at 433nm corre- sponding to that of Surface Plasmon Resonance of silver nanoparti- cles. The FTIR analysis showed the presence of aromatic, aliphatic and amines and these observations suggested the presence and binding of organic compounds with silver nanoparticles. Keywords Silver nanoparticles; Catalytic activity; Antimicrobial applications *Corresponding author: Stephen Nyoni, Department of Chemistry, Bindura University of Science Education, P. Bag 1020, Bindura, Zimbabwe, E-mail: nyonistephen@yahoo.com Received: June 02, 2017 Accepted: May 16, 2017 Published: May 21, 2017 ranging from bio sensing and catalysis to optics, antimicrobial activity, computer transistors, electrometers, chemical sensors, and wireless electronic logic and memory schemes [2]. he chemical, physical and biological properties of the nanoparticles in this range changes in fundamental ways from the properties of both individual atoms/molecules and of the corresponding bulk materials. Nanoparticles are present in several diferent morphologies such as spheres, cylinders, platelets, tubes and can be made of materials of varied chemical nature, the most common being metals, metal oxides, silicates, non-oxide ceramics, polymers, organics, carbon and biomolecules. Silver nanoparticles are of interest because of the unique properties (size and shape depending optical, electrical, and magnetic properties) which can be incorporated into antimicrobial applications, biosensor materials, composite ibers, cryogenic superconducting materials, cosmetic products, and electronic components. Several physical and chemical methods have been used for synthesizing and stabilizing silver nanoparticles [3]. he most popular chemical approaches, including chemical reduction using a variety of organic and inorganic reducing agents, electrochemical techniques, physicochemical reduction, and radiolysis are widely used for the synthesis of silver nanoparticles. Recently, nanoparticle synthesis is among the most interesting scientiic areas of inquiry, and there is growing attention to produce nanoparticles using environmentally friendly methods (green chemistry). Green synthesis approaches include mixed-valence polyoxometalates, polysaccharides, Tollens, biological, and irradiation methods which have advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthesis of silver AgNPs is cost efective and environmentally friendly relative to chemical and physical methods. his involves the synthesis of AgNPs by plant extracts and silver nitrate solution. In this synthesis phytochemical compounds in the plant extracts are responsible for the bio reduction of Ag + ions to AgNPs. he main phytochemicals involved are terpenoids, lavones, ketones, aldehydes, amides, and carboxylic acids. In this work, Euphorbia Coninalis (chikondekonde) stem extracts were used for the irst time to synthesize AgNPs. We selected Euphorbia Coninalis because it has been reported that the Euphorbia family’s (Euphorbiaceae) white latex contain oils, keto steroids, glycosides, couroupitine, indirubin, isatin, phenolic compounds, lavonoids, and terpenoids [4]. We exploited the presence of these compounds to perform the reduction of Ag + ions to form AgNPs. Furthermore, Euphorbia Coninalis is an indigenous plant in Zimbabwe and is readily found in rocky hills in deciduous woodland but without any current commercial application. Again, the tree has varied traditional medicinal uses in Zimbabwean communities which include treatment of lesions, wounds on cattle, treating warts, tumors, skin diseases and tooth ache. By synthesizing AgNPs using Euphorbia Coninalis plant extracts we also envisage the addition of these medicinal properties/ functionalities to the AgNPs, resulting in combinational antimicrobial activity. A drug with such combinational or synergistic properties can result in combating incidences of drug resistance against pathogenic Introduction he term nanoparticle is used to describe a particle with size in the range of 1nm-100nm, at least in one of the three possible dimensions. Nanoparticles are of great interest due to their extremely small size and large surface to volume ratio, which lead to both chemical and physical diferences in their properties compared to bulk of the same chemical composition, such as mechanical, biological and sterical properties, catalytic activity, thermal and electrical conductivity, optical absorption and melting point [1]. Designing and production of materials with novel applications can be enhanced by controlling shape and size at nanometer scale. Nanoparticles exhibit size and shape-dependent properties which are of interest for applications