Gold Nanoparticle Cluster Arrays for High‐Performance SERS Substrates Fabricated by Electro‐oxidative Lithography

The availability of high-performance substrates for surface enhanced Raman spectroscopy (SERS) in a reproducible fashion is of tremendous importance for transferring the technology into a routine analysis tool. We describe the fabrication of highly efficient SERS substrates facilitating enhancement factors as high as ∼5×106 by combining self-assembly strategies with electro-oxidative nanolithography, which allows the fabrication of cluster arrays consisting of individual gold nanoparticles at ambient conditions and at low costs. Different aspects on the fabrication process, that is, the optimization of the cluster distances, the contribution of intra- and interparticle plasmon coupling, as well as the determination of the signal enhancement and substrate reproducibility, are discussed.