Biosynthesis of silver nanoparticles using extract of olive leaf: synthesis and in vitro cytotoxic effect on MCF-7 cells

Abstract

A green synthetic approach using olive leaf extract was optimized for preparing silver nanoparticles (AgNPs). Parameters affecting the formation of nanoparticles such as temperature, exposure time to extract, pH, concentration of silver nitrate, and extract (ratio of plant sample to extraction solvent) were investigated and optimized. Optimum conditions for the synthesis of silver nanoparticles are as follows: Ag+ concentration 1 mM, extract concentration, 8 % w/v; pH = 7, time, 4 h and temperature, 45 °C. Synthesized silver nanoparticles were characterized using UV–Visible absorption spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, dynamic light scattering (DLS), and scanning electron microscopy (SEM). SEM and DLS analysis showed that the synthesized AgNPs were predominantly spherical in shape with an average size of 90 nm. The cytotoxicity activities of the synthesized AgNPs and olive leaves extract containing AgNPs against human breast cancer cell (MCF-7) were investigated and the inhibitory concentration (IC50) was found to be 50 and 0.024 μg/mL at 24 h incubation, respectively. This eco-friendly and cost-effective synthesis method can be potentially used for large-scale production of silver nanoparticles.