Controlling Gold Electrodeposition on Porous Polymeric Templates Produced by the Breath-Figure Method: Fabrication of SERS-Active Surfaces

Porous structured surfaces decorated with gold nanoparticles can be fabricated in an economical two-step process. Sub-micrometric porous polymethyl methacrylate (PMMA) templates are formed by using the breath-figure method (BFM) with a single-step spin-coating onto a conducting substrate to result in a set of delimited microdomains for gold electrodeposition. By controlling electrochemical parameters, distinct morphologies are engendered, among them, nanoparticles that present useful local Raman enhancement in the order of up to 10⁶ with stability of a solid-phase platform and characteristic chemical resistance of gold. The spatial confinement of metallic structures resulted in electromagnetic field enhancement, here compared to flat metallic surfaces where contributions of area effect and fluorescence quenching are responsible for a significant apparent enhancement to Raman spectra that has not been frequently reported to date.