Surface-enhanced Raman scattering enhancement due to localized surface plasmon resonance coupling between metallic nanoparticles and substrate

In this study, gold nanostructures (AuNSs) and silver nanoparticles (AgNPs) were integrated with a silver micro-flower-like structure deposited on a screen-printed carbon electrode (AgMF-SPCE) for enhancing surface-enhanced Raman scattering (SERS) by using 4-mercaptobenzoic acid (4-MBA) as a Raman reporter. SERS was enhanced by approximately 3.6–52.1-fold, depending on the frequency of the incident laser, the localized surface plasmon resonance frequency of metallic NPs, and particle–particle aggregation effects. Compared with AgNP/SPCE and AgMF-SPCE substrates, the AgNP/AgMF-SPCE substrate showed high temperature tolerance and long-term durability. Furthermore, the proposed substrates easily obtained hot spots for other Raman reporters such as 4-aminothiophenol, 5,5′-dithiobis-2-nitrobenzoic acid, and 4-chlorothiophenol. A linear relationship was found between the Raman signal and the concentration of Raman reporters in the range 10 nM–100 μM, with the limit of detection in the range of 6.19–77.2 nM at a signal-to-noise ratio of 3.0. These results suggest that the AgNP/AgMF-SPCE substrate will be well suited for quantitative analysis.