Tape of the truth: Ta2O5 nanopore array formed under broad potential range and SERS potential after silver sputtering

The deposition of a plasmonic metal layer on a nanostructured oxide surface is one of the important methods of preparing a platform for surface-enhanced Raman scattering (SERS) measurements. In this contribution, we describe the formation of SERS substrates by the deposition of a silver layer on ordered a Ta2O5 nanopore array. The influence of various experimental anodization process parameters on the morphology of a Ta2O5 nanopore array was carefully studied. It was found that the formation of a Ta2O5 nanopore array is possible under a broad potential range (15–50 V) in a highly acidic solution containing F− ions. In some cases, the nanopore array structures were covered by an outer layer rich in F− and SO42− ions, which could easily be removed using adhesive tape or by sonication. The deposition of an Ag layer led to SERS activity. The optimal Ag layer thickness was specified based on SEM and DRS measurements. The SERS substrates formed exhibited high point-to-point, sample-to-sample and time durability.