Selection of Highly SERS-Active Nanostructures from a Size Gradient of Au Nanovoids on a Single Bipolar Electrode

As surface‐enhanced Raman scattering (SERS) crucially depends on the morphology of nanostructured metal surfaces, we developed a convenient approach to produce a size gradient of truncated spherical Au nanovoids on a single bipolar electrode. The continuous potential drop in solution implies a linearly changing interfacial potential difference at the wireless electrode, leading to a linearly changing rate of Au electrodeposition. Such a structural gradient enables fast and reproducible screening for those structures, evoking high SERS intensity in a particular experiment. The optimal Au deposition potential with respect to the highest SERS amplification was determined and applied for the fabrication of highly active SERS substrates. Yes SERS! A size gradient of spherical Au nanostructures on a single Au surface is obtained from bipolar Au electrodeposition to find optimal nanovoid dimensions for the highest SERS enhancement. The potential associated with the best structures is determined and applied to obtain highly active SERS surfaces.