Design and Experimental Demonstration of Pyramidal SERS Substrates with High-Throughput Fabrication Method

Surface-enhanced Raman spectroscopy (SERS) is a technique based on the Raman scattering effect that provides rapid, label-free identification capabilities with very high sensitivity and specificity down to the molecular level. Due to the nature of the applications, not only are sensitivity and specificity important, but also the reproducibility of substrates is a key aspect. In this study, a design methodology for arrays of pyramid-shaped gold nanostructures is presented along with the development of a fabrication process that enables high-throughput substrate production. Using simulations of the 3D finite element method, SERS substrates with theoretical enhancement factors on the order of 10⁸ have been obtained. SERS experiments with the fabricated structures resulted in an enhancement of approximately 1500% compared to flat gold substrates. The thorough investigation of the structure, allied with a novel fabrication process that eliminates the need for complex and time-consuming lithography steps for each individual substrate, paves the way for an efficient method to produce high-quality SERS substrates.