Single-Shot Cm-Scale Plasmonic Nanogaps for Trace Detection of Chemical Compounds

Abstract

Here, we report a rapid, single-shot interference lithography strategy for the fabrication of wafer-scale, highly ordered metallic nanogap arrays with nanoscale precision. The resulting structures exhibit uniform sub-10 nm gap features across centimeter scales, yielding dense plasmonic hotspots. To assess optical performance, the arrays were employed as surface-enhanced Raman spectroscopy (SERS) substrates using a self-assembled monolayer of biphenyl-4-thiol as a standard Raman reporter. The substrates demonstrate strong Raman enhancement, confirming efficient electromagnetic field localization and high device reliability, ideal for trace detection of chemicals via SERS and various vibrational spectroscopies.