Eсо-friendly nanotechnologies: synthesis of silver nanoparticles using medicinal plants extracts

Abstract

Green synthesis of metal nanoparticles (NPs) using plant extracts is a nontoxic and ecofriendly method as compared to chemical and physical methods. The production of nanoparticles with plant extract usage has an important advantages. The aim of our research was to establish the conditions for biogenic synthesis of silver nanoparticles using extracts of the medicinal plants and in vitro cultures of medicinal plants. Plant phenolic compounds with strong oxidation-reduction properties can serve as reducing agents of metal ions to NPs. So for the technology of biogenic synthesis of NPs elaboration the most important stage is to choice the plant which will play a role of «biofactory». The medicinal plants and in vitro cultures of medicinal plants have been screened on the biologically active substances (BAS) content, because BAS are the reducing agents for silver nitrate. The phenolic compounds quantitative content screening have revealed that Silybum marianum, Agastache rugosa, Melittis sarmatica and Digitalis purpurea are the best candidates for NPs synthesis. The various factors affecting on the number of synthesized silver nanoparticles have been determined. These factors are: the concentrations of silver nitrate and reducing agents, the time of synthesis, the temperature and pH of reaction medium. The primary conditions for AgNPs synthesis in Agastache rugosa, Silybum marianum, Melittis sarmatica and Digitalis purpurea extracts have been established. The maximum yield of AgNPs in Agastache rugosa and Digitalis purpurea extracts were observed at 24 C, for Melittis sarmatica -at 35 C and for Silybum marianum extract -at 18 C. The optimal conditions for AgNPs synthesis -pH 9,0 and AgNO 3 concentration in solution -1  10 -2 M.