Study on the SERS substrate composed of Au@Ag core-shell nanoparticles linked to SiO₂ spheres

ABSTRACT

We have developed a sensitive surface-enhanced Raman scattering (SERS) substrate composed of 60-nm Au@Ag core-shell nanoparticles linked to 360-nm SiO₂ sphere base, which experimentally demonstrated that the detection limits for p-aminothiophenol (PATP), Rhodamine 6G (R6G) and 5,5-dithiobis(2-dinitrobenzoic acid) (DTNB) could be 10⁻¹³, 10⁻¹³ and 10⁻¹² M, respectively. The fabrication method of the SERS substrate and the experimental investigation on the enhancement performance of the substrate are presented in detail in this article. The results show that the 360 nm SiO₂-60 nm Au@Ag nanocomposites could be used as an excellent substrate for SERS detection of small organic molecules.

KEYWORDS:

• SERS
• Au@Ag core-shell nanoparticles
• SiO₂ sphere base
• Rhodamine 6G (R6G)
• p-aminothiophenol (PATP)
• 5,5-dithiobis(2-dinitrobenzoic acid) (DTNB)

Acknowledgments

The authors are indebted to the National Natural Science Foundation of China (61308103) and the National High Technology Research and Development Program of China (2012AA022007).