Preparation and properties of gold nanoparticles stabilized by abietic acid

Abstract

Hydrophobic gold nanoparticles were prepared via the reduction of HAuCl4 by sodium borohydride in the presence of abietic acid (AA) in nonaqueous polar media based on dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, and isopropanol. The particles prepared in DMF had spherical gold cores, with a narrow size distribution and the average diameter d Au = 7.1 ± 1.0 nm, and a protective shell formed of abietic acid anions and sodium cations. A violet nanoparticle sediment separated by centrifugation was stored under DMF and could be used for preparing colloidal dispersions of nanoparticles in polar solvents. Ethanol dispersions of nanoparticles were most resistant to sedimentation. The nanoparticles were shown to be useful for sensing nonaqueous polar media.