Where silver nanoparticles with other numbers of atoms structure differently from gold, the behavior of [Ag25(SR)18] is so similar in structure to its well-studied gold equivalent that the authors argue it "offers the first model nanoparticle platform to investigate the centuries-old problem of understanding the fundamental differences between silver and gold in terms of nobility, catalytic activity, and optical property." The question is important because silver is so toxic, it is used for antibacterial coatings; whereas gold is so unreactive, it is biologically safe.
