Surface-enhanced Raman scattering-active silver nanostructures with two domains

Generally, a controllable and reproduced surface roughness for surface-enhanced Raman scattering (SERS) studies can be generated through control of the electrochemical oxidation–reduction cycles (ORC) procedure. In this work, we propose a new sonoelectrochemical approach to prepare SERS-active substrates with two domain-Ag nanostructures. The method is based on a strategy of deposition–dissolution cycles (DDCs) by using a cathodic overpotential and an anodic overpotential from open circuit potential (OCP) in turn under sonication. The prepared SERS-active substrate demonstrates large Raman scattering enhancement for adsorbed Rhodamine 6G (R6G) with an enhancement factor of 2.3 × 108 and a limit of detection of 2 × 10−13 M. The improved SERS performances can be successfully explained from the viewpoints of electromagnetic (EM) and chemical (CHEM) enhancements.

Graphical abstractSEM image of Ag NSs-deposited Pt substrate prepared by sonoelectrochemical deposition–dissolution cycles under a cathodic overpotential of 0.6 V and an anodic overpotential of 0 V from OCP with a ratio of reaction times of deposition to dissolution of Ag NSs to be 0.2.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Prepare new SERS-active substrates with two domain-Ag na nostructures. ► The method is based on a strategy of electrochemical deposition–dissolution cycles. ► Raman scattering enhancement for R6G with an enhancement factor of 2.3 × 108.