BIOLOGICAL AND PHYSICOCHEMICAL PROPERTIES OF GOLD AND IRON NANOPARTICLES PRODUCED BY GREEN SYNTHESIS METHOD

Abstract

Gold and iron nanoparticles were generated via environmentally safe metal-vapor synthesis method applying acetone or toluene as organic dispersion medium. Biological properties of the nanoparticles were analyzed by the agar disc diffusion method using Gram-positive and Gram-negative bacteria and via in vitro cytotoxicity assays with different human cell lines. The obtained results revealed distinct biological activity profiles of the studied specimens. Fe nanoparticles (Fe NPs) demonstrated inhibitory effects against both Gram-positive and Gram-negative bacteria. Au nanoparticles (Au NPs) produced in acetone as organic dispersion medium reduced the growth of E. coli, but showed lower activity against the Gram-positive bacterium B. cereus. Au NPs derived from toluene organosol demonstrated the lowest level of antibacterial activity. In vitro analyses with human cells indicated mild cytotoxic effects of Au NPs against all tested cell lines. Fe NPs demonstrated time- and concentration-dependent cytotoxicity against colon adenocarcinoma cells. Iron nanoparticles derived from acetone organosol did not induce negative effect on noncancerous human cells, which indicates a good biocompatibility potential. Their physicochemical properties were characterized by transmission and scanning electron microscopy (TEM, SEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). TEM observations demonstrated that Au NPs and Fe NPs have average sizes of 8.3 nm and 1.8 nm. Characteristics of the photoelectron spectra showed that gold is in the state of Au0, and the spectrum of iron is close in shape to the spectrum of Fe3O4.