Enhancement of Raman intensity due to the electrochemical surface-enhanced Raman scattering (EC-SERS) effect is an interesting alternative to overcome the lack of sensitivity traditionally associated with Raman spectroscopy. Furthermore, activation of metallic screen-printed electrodes (SPEs) by electrochemical route leads to the reproducible generation of nanostructures with excellent SERS properties. EC-SERS procedure proposed in this work for the detection of several pesticides (thiram, imidacloprid and chlorpyrifos) with different nature, uses gold SPEs as SERS substrates, but also includes a preconcentration step as the initial and essential stage. Taking into account the small volume of solution employed, only 60 µL, the preconcentration cannot be performed for more than 15 minutes in order to ensure the proper contact of the solution with WE, RE and CE. Furthermore, selected temperature, 34 °C, is not very high to allow the exhaustive control of the drop volume. Optimization of preconcentration parameters (time and temperature) displays a crucial step, particularly in the detection of low concentrations of pesticides, because it will provide higher Raman intensity in EC-SERS experiments. After the initial step, gold SPEs were electrochemically activated by cyclic voltammetry, allowing the detection of very low concentration (µg·L^-1) of pesticides due to the generation of fresh nanostructures with SERS effect.

由于电化学表面增强拉曼散射（EC-SERS）效应而引起的拉曼强度增强是克服传统上与拉曼光谱法相关联的灵敏度不足的有趣替代方法。此外，通过电化学途径活化金属丝网印刷电极（SPE）导致可再现地生成具有出色SERS特性的纳米结构。这项工作中提出的EC-SERS程序用于检测几种性质不同的农药（噻喃，吡虫啉和毒死rif），使用金SPE作为SERS底物，但还包括预浓缩步骤，作为初始且必不可少的步骤。考虑到所用溶液的体积很小，只有60 µL，预浓缩时间不能超过15分钟，以确保溶液与WE，RE和CE正确接触。此外，选定的温度34°C不太高，无法完全控制液滴的体积。预浓缩参数（时间和温度）的优化显示了至关重要的一步，尤其是在检测低浓度农药时，因为它将在EC-SERS实验中提供更高的拉曼强度。初始步骤后，通过循环伏安法将金SPE电化学活化，从而可检测出极低的浓度（µg·L 特别是在低浓度农药检测中，因为它将在EC-SERS实验中提供更高的拉曼强度。初始步骤后，通过循环伏安法将金SPE电化学活化，从而可检测出极低浓度（µg·L 特别是在低浓度农药检测中，因为它将在EC-SERS实验中提供更高的拉曼强度。初始步骤后，通过循环伏安法将金SPE电化学活化，从而可检测出极低浓度（µg·L^-1）的农药，因为它产生了具有SERS效应的新鲜纳米结构。