Biogenic synthesis of stable bioactive silver chloride nanoparticles using Onosma dichroantha Boiss. root extract

Biogenic synthesis of nanoparticles, which employs biomolecules as reducing and stabilizing agents has recently attracted tremendous attention; mainly due to its lower cost and less toxic byproducts. Here, for the first time, we studied the ability of a medicinal plant belonging to the Boraginaceae family - Onosma dichroantha Boiss. - root extract in synthesis of nanoparticles from silver nitrate, at room temperature. The kinetics of the reaction correlated well with applied concentrations of the plant extract. Fourier-transform infrared spectroscopy further suggested extract components, capable of bio-reduction and stabilization of nanoparticles. X-ray diffraction pattern and transmission electron microscopy revealed that 1 mM of AgNO3 produced mostly spherical AgCl nanoparticles in a range of 5-65 nm in diameter. Remarkably, the synthesized nanoparticles showed significant inhibitory effects against Escherichia coli and Staphylococcus aureus clinical isolates. Altogether, these data suggest a new promising approach for a merged clinical application of a medicinal plant and bioactive nanoparticles. (C) 2014 Elsevier B.V. All rights reserved.