Rhodiola rosea extract mediated green synthesis of silver nanoparticles supported by nanosilica carrier

Silver nanoparticles exhibit beneficial bactericidal and fungicidal properties that make them an object of interest for pharmaceutical, cosmetics and agricultural industries. However, commonly used methods for obtaining nanosilver particles use synthetic polymers and toxic compounds that are harmful to the environment. Currently for the nanoparticles synthesis, natural reagents and inter substances such as plant extracts and silica are often applied. This work describes two approaches for silver nanoparticles on colloidal silica carrier preparation by chemical reduction using NaBH4 as a reductor and Rhodiola rosea extract as a stabilizing-reducing agent. Extract properties were determined by total phenolic compounds content by Folin-Ciocalteau reaction and total antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl reagent. The impact of various parameters on synthesis efficiency such as: time, temperature, silver and stabilizer concentrations as well as the amount of colloidal silica has been investigated. Physicochemical characteristics of selected nanosilver suspension was specified by instrumental methods such as: scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS). Moreover, stability of obtained products was monitored and described using UV-Vis spectrophotometry.