New Strategies for the Improvement of EC-SERS Effect in Organic Solvents

Abstract

Over the last years, combination of electrochemistry (EC) and surface-enhanced Raman scattering (SERS) has received growing attention due to the powerful features associated with EC-SERS effect. In particular, electrochemical activation of metal electrodes allows the generation of SERS substrates which provides the enhancement of Raman intensity in a single experiment. Although effective electrochemical methods have been developed [1,2], they are traditionally limited to aqueous solutions. Raman spectroelectrochemistry in organic media is an interesting alternative, but the development of new EC-SERS procedures is still required.In this work, different organic solvents were tested for the improvement of Raman features by EC-SERS. Taking into account that organic solvents usually have many Raman bands (Figure 1) that could hamper the analysis of the characteristic bands of the molecule of interest, the selection of the solvent must be considered for each application. As proof of concept, the detection of nicotinamide in organic media is carried out by the electrochemical activation of Au electrode. Electrochemical protocol based on an initial oxidation of the electrode surface followed by its reduction, allows the generation of SERS substrates and provides the enhancement of the Raman signal.Figure 1. Raman spectra of ACN, EtOH, DMSO, DMF and THF.