Investigation of SERS Studies on Periodic Patterned ZnO Nanorod Array Fabricated Using Silica Inverse Opal Nanostructure as a Template

In this study, we combined metal oxide semiconductor nanomaterials with metal nanoparticles (NPs) to fabricate surface-enhanced Raman scattering (SERS) substrates and investigated their enhancement effects. Among the various metal oxide semiconductors, zinc oxide (ZnO) was chosen as the candidate due to its numerous advantages, including low processing temperature and the capability to form diverse nanostructures. Additionally, four different structured SERS substrates are designed to gain a deeper understanding of the impact of using two-dimensional planar structures versus three-dimensional structures, as well as the influence of structural periodicity on the sensitivity of the resulting SERS substrate in Raman scattering intensity. Herein, rhodamine 6G (R6G) is used as a probe molecule to explore the magnitude of the enhancement factor (EF) for the four different structured SERS substrates under varying Ag NPs decoration times. Simultaneously, we prepared R6G solutions at different concentrations to analyze the limit of detection (LOD) for the four different structured SERS substrates. The results indicated that when utilizing a periodic patterned ZnO nanorod array (NAR) as a SERS substrate, its EF value could reach 1.8 × 10¹⁰ with a LOD of 10^-13 M.