Raman signal enhancement of low-cost metal sheet SERS with gold decoration

Surface Enhance Raman Spectroscopy (SERS) is a sensitive surface creating plasmonic resonance for the Raman scattering. SERS is considered as a powerful technique to enhance the Raman signal, when quantity of sample is limited. Recently, our lab team has discovered a low-cost SERS template fabrication, laser-engraving method, which is suitable with gold nanoparticles decoration. In this work, two different materials, zinc, and copper, were used as metal sheet SERS substrate. Gold nanoparticles sputtered with 270 s of sputtering time were used as decorated noble metal. FE-SEM images illustrated the nano-in-microstructure of the engraved metal sheets. The decorated Au nanoparticles were uniform and fully cover on the rough metal sheet templates. From contact angle measurement with DI water, Zn/Au SERS provided the highest contact angle, which was 142.10 +/- 0.51 degree. SERS performance, including Enhancement Factor (EF), Limit of Detection (LOD), and shelf-life were investigated. The EF values of Zn/Au SERS and Cu/Au SERS were 7.40 x 10(9) and 1.70 x 10(8), respectively. From LOD results, Zn/Au SERS presented the great ability to enhance the Raman signal at 10(-7) molar concentration. However, after 90 days of shelf-life test, both showed the capability to enhance the Raman signal.