Raman scattering enhancement using crystallographic surface of a colloidal crystal

Abstract

Deposition of coinage metals on a crystallographic surface of a colloidal crystal is proposed with the aim of fabricating metal surfaces with a regular relief on a scale of 200–300 nm to get strong surface-enhanced Raman scattering (SERS). The approach is implemented through thin gold-film deposition on a surface of a crystal consisting of silica globules. Mitoxantrone molecules, a DNA intercalator, were used to prove high SERS efficiency of the structures proposed. As compared to other SERS-active substrates, metal-dielectric colloidal crystal structures possess well-defined surface parameters (globule diameter and film thickness), high stability and reproducibility. These advantages are important for systematic analysis of SERS mechanisms in mesoscopic structures and its application in single-molecule detection.