Fast Screening of Pesticides By Raman Spectroelectrochemistry Based on EC-SERS Effect

Abstract

Electrochemical Surface-enhanced Raman spectroscopy (EC-SERS) effect is an outstanding procedure that ensures the enhancement of Raman signal, a careful control of the nanostructures prepared and the possibility of detecting different analytes while the substrate preparation is taking place. Development of novel EC-SERS procedures provide these benefits in the simultaneous preparation and measurement process [1,2], and open new gates for analytical applications. Activation of metallic screen-printed electrodes (SPEs) by electrochemical routes leads to the generation of reproducible nanostructures with excellent SERS properties. In that way, gold, silver and copper SPEs circumvent the traditional reproducibility limitation and produce the enhancement of the Raman intensity to favor the detection of low concentrations.In this work, detection of different pesticides was achieved by the development of new electrochemical activation procedures using metallic SPEs as SERS substrates (Figure 1). The obtained results demonstrate that Raman spectroelectrochemistry is a powerful technique for monitoring the levels of pesticides, being this study the previous step in their detection in real samples.Figure 1. Raman spectrum of thiram obtained during a cyclic voltammetry using Ag SPE.