Preparation of gold nanoparticles using chitosan oligosaccharide as a reducing and capping reagent and their in vitro cytotoxic effect on Human fibroblasts cells

•Low molecular chitosan oligosaccharide mediated synthesis of gold nanoparticles was assessed.•Chitosan oligosaccharide are responsible for the formation and stabilization of nanoparticles.•The synthesis method is rapid, simple and cost-effective.•Gold nanoparticles exhibit cytotoxic effect on Human fibroblasts cells.

Gold nanoparticles (GNPs) were successfully synthesized by use of chitosan oligosaccharide (COS) as reducing agent and capping agent. The results revealed that the average particle size was 115.21±16.87 nm and were crystallized in the face centered cubic symmetry. The possible synthesis mechanisms were elucidated through FTIR. In vitro cytotoxicity of the GNPs against Human fibroblasts cells showed a dose–response activity at concentration higher than 62.5 μg/ml.