Fabrication of large scale uniform copper-island thin film for ultrasensitive surface enhanced Raman scattering

Abstract

Nanostructured metals with designable and controllable structures have received increasing attention in surface enhanced Raman scattering (SERS) due to the single molecular detection limit. Great challenges still remain in creating large scale substrates with high-density ‘hotspots’ to provide a uniform and stable enhancement of Raman signals. Here, we fabricated a copper island thin film over an 80 cm2 scale substrate with tunable particle sizes by combining sputtering with dealloying processes. The island size can be tailored from 150 nm to 370 nm by controlling parameters and etching conditions and possesses an optimized surface morphology structure. The detection limit of crystal violet (CV) molecules reached 0.1 pM. Meanwhile, the copper island thin film presents good homogeneity and stability. Our method is promising to repeatedly fabricate novel metal SERS substrates on a large scale with standard properties for sensing applications.

Application of the analytical quality by design principles to the development of a qualitative surface‐enhanced Raman scattering method: A proof of concept

“…Therefore, it is commonly used as a model compound to develop SERS methods or to conduct fundamental studies. [ 35–37 ] Another element that was taken into consideration was the solubility of CV in both water and alcohols, allowing the evaluation of the effect of the use of a different solvent as well. This aspect was essential for the study because the solvent present in the SERS medium affects the NP aggregation process and then the SERS enhancement.…”