Facile fabrication of triple-layer (Au@Ag)@polypyrrole core-shell and (Au@H2O)@polypyrrole yolk-shell nanostructures

Triple-layer (Au@Ag)@polypyrrole core-shell nanoparticles are fabricated by a one-step synthesis involving simultaneous reduction of AgNO3 and polymerization of pyrrole in the presence of Au nanoparticles; the Ag layer in the resulting nanoparticles is etched to give a (Au@H2O)@polypyrrole yolk-shell structure.