Hierarchical Nanoparticle Assemblies Formed via One-Step Catalytic Stamp Pattern Transfer.

The one-step catalytic stamp pattern transfer process is described for producing arrays of hierarchical nanoparticle assemblies. The method simply combines in situ nanoparticle synthesis triggered by free residual Si-H groups on PMDS stamps and lift-off pattern transfer technique. No additional nanoparticle synthesis procedure is required before pattern transfer process. Exquisitely uniform and precisely spaced hierarchical nanoparticle assemblies with designed geometry can be rapidly produced using catalytic stamp pattern transfer process. Sequential catalytic stamp pattern transfer also is described to generate multilayered, hierarchical nanoparticle assemblies with various geometries. The hierarchical nanoparticle assemblies catalytically transferred onto the surface is not just nanoparticles, but nanoparticle-PDMS residue composites. The in situ synthesized nanoparticles still remain optical properties. The hierarchical nanoparticle assemblies with precisely controlled geometry further show potential in the application of surface-enhanced Raman scattering. Capability of the one-step catalytic stamp pattern transfer allows the scalable and reproducible fabrication of well-defined hierarchical nanoparticle assemblies.