Raman scattering enhancement using crystallographic surface of a colloidal crystal

Deposition of coinage metals on a crystallographic surface of a colloidal crystal is proposed to fabricate metal surface with a regular relief on a scale of $200$–$300$ nm to get strong surface enhanced Raman scattering (SERS). The approach is performed by means of a thin gold film deposition on a surface of a crystal consisting of silica globules. Mitoxantrone molecules, a DNA intercalator, have been 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 molecules detection.