SYNTHESIS OF AG0NANOPARTICLES FROM EXTRACT AND ETHANOLIC AND AQUEOUS FRACTIONS OF LEAVES AND PETALS OF HIBISCUS ROSA-SINENSIS L.

Abstract

The synthesis of nanoparticles from plant extracts has become an interesting line of research in recent years. The purpose of the study was the synthesis of silver nanoparticles (AgNPs) from silver nitrate, aqueous and ethanol 80% extracts obtained by ultrasound-assisted extraction, as well as fractions of chloroform, ethyl acetate and water, of flower petals and leaves of Hibiscus rosa-sinensis L. The ethanolic extract of petals of H. rosa-sinensis L. was analyzed by UHPLC-ESI-Q-Orbitrap- MS/MS identifying pelargonidin, petunidin, kaempferol, and orientin. Characterization of AgNPs by UV-Visible spectrophotometry gave a λmax at 400,631 nm and 389,411 nm for AgNPs obtained with ethanolic extract of flower petals and leaves, λmax at 402,270 nm and 391,057 nm for AgNPs of aqueous extracts of flower petals and leaves respectively. FTIR confirmed the reduction of Ag+ ions to Ag0 ions in AgNPS. Dynamic light dispersion (DLS) showed an effective diameter of the AgNPS from extracts, less than 80 nm and for AgNPs from fractions was less at 53 nm and near-zero polydispersity indices. Electron field emission scanning microscopy (FE-SEM) showed a particle size between 17 - 32 nm for AgNPs from extracts, and 15 - 26 nm for AgNPs from fractions, which showed a spherical structure. X-ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) analysis confirmed the elemental composition of AgNPs showing mostly silver (60.44%), oxygen (32.48%) and potassium (4.97%). This study revealed that the compounds from the extracts of Hibiscus rosa-sinensis L. are good reducing and stabilizing agents for the synthesis of silver nanoparticles, being pH 9 optimal for synthesis.