Dendrimer-mediated synthesis and shape evolution of gold-silver alloy nanoparticles

► Au-Ag alloy NPs can be formed using dendrimers as both stabilizers and reductants. ► The metal composition and surface modification greatly affect the NPs' properties. ► The alloy NPs experience a shape evolution with metal atom/dendrimer molar ratio. ► Metal composition and surface groups affect the NPs' X-ray attenuation property.