Highly Sensitive and Reproducible SERS Substrates Based on Ordered Micropyramid Array and Silver Nanoparticles

The construction of a highly sensitive and reproducible surface-enhanced Raman scattering (SERS) substrate is the key factor that restricts its practical application. In this paper, a three-dimensional (3D) SERS substrate based on ordered micropyramid array and silver nanoparticles (MPA/AgNPs 3D-SERS) was constructed using the roll-to-plate embossing technology and a hydrothermal method, which provided an efficient and low-cost preparation process for the SERS substrate. Using rhodamine 6G (R6G) as a probe molecule, the performance of an MPA/AgNP 3D-SERS substrate was studied in detail, whose minimum detection limit was 10^-12 M and the enhancement factor was calculated as 8.8 × 10⁹, indicating its high sensitivity. In addition, the minimum relative standard deviation (RSD) for the MPA/AgNP 3D-SERS substrate was calculated as 4.99%, and SERS performance basically had no loss after 12 days of placement, which indicated that the prepared SERS substrate had excellent stability and repeatability. At last, the thiram detection application of the MPA/AgNP 3D-SERS substrate was also investigated. The results showed that the minimum detection limit was 1 × 10^-7 M, and quantitative analysis of pesticide residues could be realized. This research could provide useful guidance for the efficient and low-cost fabrication of highly sensitive and reproducible SERS substrates.