Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

Abstract

SummaryAlloyed silver–gold nanoparticles were prepared in nine different metal compositions with silver/gold molar ratios of ranging from 90:10 to 10:90. The one-pot synthesis in aqueous medium can easily be modified to gain control over the final particle diameter and the stabilizing agents. The purification of the particles to remove synthesis by-products (which is an important factor for subsequent in vitro experiments) was carried out by multiple ultracentrifugation steps. Characterization by transmission electron microscopy (TEM), differential centrifugal sedimentation (DCS), dynamic light scattering (DLS), UV–vis spectroscopy and atomic absorption spectroscopy (AAS) showed spherical, monodisperse, colloidally stable silver–gold nanoparticles of ≈7 nm diameter with measured molar metal compositions very close to the theoretical values. The examination of the nanoparticle cytotoxicity towards HeLa cells and human mesenchymal stem cells (hMSCs) showed that the toxicity is not proportional to the silver content. Nanoparticles with a silver/gold molar composition of 80:20 showed the highest toxicity.

Electrochemistry at single bimetallic nanoparticles – using nano impacts for sizing and compositional analysis of individual AgAu alloy nanoparticles

“…For an extended X-ray diffraction and TEM-EDX analysis of the alloy nanoparticles we refer to Ristig et al, 15,36 who demonstrated that the used synthesis method produces AgAu alloy nanoparticles of adjustable composition, with an increased Au content in the center of the particle. In agreement to their nding, the UV-vis absorption spectrum (Cary 60 UV-vis spectrophotometer by Agilent Technologies Inc.) of the nanoparticle suspension used herein showed a plasmon resonance absorption peak at 447 nm (see Fig.…”

Nanostructure of wet-chemically prepared, polymer-stabilized silver–gold nanoalloys (6 nm) over the entire composition range

“…19 This in turn will determine their chemical and biological effects, e.g. the release of silver ions for antibacterial activity 20 and the presence of gold on the nanoparticle surface for a stable subsequent covalent functionalization.…”

Synthesis of Au doped Ag nanoclusters and the doping effect of Au atoms on their physical and optical properties

“…The absorption peak of the as-synthesized Ag/Au NCs shifts to the ultraviolet region ( figure 1(a)). This manifests two phenomena, the first one is due to the higher molar ratio of Ag with respect to Au precursor [15,31]. As for pure Ag NCs absorption peak is in the UV region (ca.…”