Nanoporous silver with tunable pore characteristics and superior surface enhanced Raman scattering

• Nanoporous silver was produced by dealloying Ag-based metallic glasses.
• Pore characteristics of nanoporous silvers can be tuned by dealloying conditions.
• Nanoporous silver substrate showed superior surface Raman scattering capability.

We report the development of three dimension (3D) nanoporous silvers by electrochemical dealloying specially designed Ag-based metallic glasses. It was found that the nanoporosity could be tailored by the dealloying conditions and chemical compositions of glassy precursors. The resultant 3D nanoporous metals exhibited superior surface enhanced Raman scattering capacity for rhodamine 6G molecules, which is close to the level of single molecule detection. Our findings not only provide desirable functional materials for advanced sensors, but also are important for further understanding formation mechanisms of nanoporosity via dealloying glassy alloys in general.