Araújo Gleidson Thiago Sá, Faustino Lucas Costa, Silva Rejane Maria Pereira, Cantanhêde Welter, Gerôncio Everson Thiago Santos
Department of Chemistry - PPGQ, State University of Piauí, Campus Poeta Torquato Neto, Pirajá, Teresina, PI, 64002-150, Brazil.
Department of Chemistry - PPGQ, Federal University of Piauí, Campus Universitário Ministro Petrônio Portella, Teresina, PI, 64049-550, Brazil.
Mikrochim Acta. 2025 Feb 26;192(3):191. doi: 10.1007/s00604-025-07041-z.
A simple and cost-effective methodology for manufacturing a portable electroanalytical device is reported. The device is based on a graphite/polyvinyl chloride (PVC) paper-based electrode coupled to a miniaturized 3D-printed electrochemical cell (3DEC). The 3DEC was designed to ensure the reproducibility of the system by delimitating the paper-based graphite electrode (PGE) area. The disposable PGE was fabricated by paint-brushing a conductive ink based on graphite powder and toluene-free PVC glue, onto a kraft paper. Different weight proportions (wt%) of graphite/PVC were evaluated regarding mechanical stability and electrochemical behavior. Cyclic voltammetric (CV) analysis in the presence of the [Fe(CN)] redox probe has shown that as the wt% of graphite in the ink increased from 50 to 90%, a clear decrease in peak potential separation (ΔE) and increase in current are observed, indicating an improvement in charge transfer kinetics. However, 90 wt% graphite electrodes have shown poor adhesion to the substrate and easy leaching due to the small amount of PVC (binder). Therefore, the best PGE was achieved using 80:20 wt% graphite/PVC ink (PGE8020). Moreover, scanning electron microscopy (SEM) images and energy dispersive spectroscopy (EDS) mapping revealed a rugous and more uniform deposition of the conductive ink containing 80 wt% graphite. As a proof of concept, the graphite/PVC ink-based disposable electrodes were employed for the detection of 3-nitro-L-tyrosine (3-NLT) in synthetic urine samples, showing a detection limit of 2.85 μmol L, and %recovery in synthetic urine between 97 and 109%, highlighting the reliability and applicability of the proposed approach.
本文报道了一种用于制造便携式电分析装置的简单且经济高效的方法。该装置基于与小型化3D打印电化学池（3DEC）耦合的石墨/聚氯乙烯（PVC）纸质电极。3DEC的设计旨在通过划定纸质石墨电极（PGE）区域来确保系统的可重复性。一次性PGE是通过将基于石墨粉和无甲苯PVC胶水的导电油墨用画笔刷涂在牛皮纸上制成的。针对机械稳定性和电化学行为评估了不同重量比例（wt%）的石墨/PVC。在[Fe(CN)]氧化还原探针存在下的循环伏安（CV）分析表明，随着油墨中石墨的wt%从50%增加到90%，观察到峰电位分离（ΔE）明显降低，电流增加，表明电荷转移动力学得到改善。然而，90 wt%石墨电极对基底的附着力较差，并且由于PVC（粘合剂）含量少而容易浸出。因此，使用80:20 wt%石墨/PVC油墨（PGE8020）获得了最佳的PGE。此外，扫描电子显微镜（SEM）图像和能量色散光谱（EDS）映射显示含80 wt%石墨的导电油墨沉积粗糙且更均匀。作为概念验证，基于石墨/PVC油墨的一次性电极用于检测合成尿液样品中的3-硝基-L-酪氨酸（3-NLT），检测限为2.85 μmol L，合成尿液中的回收率在97%至109%之间，突出了所提出方法的可靠性和适用性。
