In the last decades, a significant amount of research has been focused on the development of miniaturized and portable electrochemical sensors in the form of screen-printed electrodes (SPEs). When performing voltammetric measurements using SPEs, especially in the case of carbon-based electrodes, additional peaks can appear and overlap with analytes’ signals or otherwise interfere with results. Therefore, the development of pretreatment methods that enable the removal of interferences is of great importance for SPEs utilization, e.g. for sensor applications. Moreover, electrode pretreatment can also be used to improve electron transfer kinetics, including reversibility of the studied redox processes. In this work, we present the evaluation of different pretreatment methods using cyclic voltammetry and potentiostatic anodization, applied on an in-house graphite-glass composite working electrodes. With the use of X-ray photoelectron spectroscopy and scanning electron microscopy it was confirmed that the surface of working electrode was contaminated by sub-micrometer sized silver particles, which resulted in two interference peaks. Several strong acids, including HSO, HNO, and HCl, as well as phosphate buffer solution, were evaluated as electrolytes for electrochemical pretreatment. A rapid, simple, and low-cost pretreatment protocol that enables the removal of the interference peaks, as well as improved voltammetric signals for [Fe(CN)] redox probe was developed. We propose the optimal pretreatment method in HSO as a protocol that could be universally applied for carbon, carbon-glass, or similar types of SPEs before performing voltammetric experiments and/or further modifications of SPEs.

中文翻译：

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一种创新的预处理方案，可消除石墨-玻璃工作电极上银污染引起的伏安干扰

在过去的几十年中，大量研究集中在丝网印刷电极（SPE）形式的小型化便携式电化学传感器的开发上。当使用 SPE 进行伏安测量时，尤其是在碳基电极的情况下，可能会出现额外的峰并与分析物的信号重叠或以其他方式干扰结果。因此，开发能够消除干扰的预处理方法对于 SPE 的利用（例如传感器应用）非常重要。此外，电极预处理还可用于改善电子转移动力学，包括所研究的氧化还原过程的可逆性。在这项工作中，我们评估了使用循环伏安法和恒电位阳极氧化的不同预处理方法，应用于内部石墨-玻璃复合工作电极。利用X射线光电子能谱和扫描电子显微镜证实工作电极表面被亚微米尺寸的银颗粒污染，从而产生两个干涉峰。评估了几种强酸，包括 HSO、HNO 和 HCl，以及磷酸盐缓冲溶液作为电化学预处理的电解质。开发了一种快速、简单且低成本的预处理方案，能够消除干扰峰，并改进 [Fe(CN)] 氧化还原探针的伏安信号。我们提出了 HSO 中的最佳预处理方法作为一种方案，在进行伏安实验和/或进一步修改 SPE 之前，该方法可普遍应用于碳、碳玻璃或类似类型的 SPE。