Castro Lucas F, Silva-Neto Habdias A, Sousa Lucas R, de Araujo William R, Coltro Wendell K T
Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO, Brazil.
Departamento de Química Analítica, Instituto de Química, Universidade Estadual de Campinas, Campinas, SP, 13083-970, Brazil.
Talanta. 2023 Jan 1;251:123812. doi: 10.1016/j.talanta.2022.123812. Epub 2022 Aug 6.
This study describes the development of electrochemical paper-based analytical devices (ePADs) using carbon-based paste combining silicone glue and graphite powder. The ePADs were manufactured using the screen-printing technique, which consisted of depositing the conductive ink on a screencast on the paper surface. In addition, an alternative electrical connector was designed and 3D-printed to make the detection method cheaper, portable and reproducible. The morphological, structural, and electrochemical properties of the conductive material developed were investigated through scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements. The ePADs combined with the alternative connector revealed high repeatability, reproducibility, and stable responses considering a well-known redox probe ([Fe(CN)]). In addition, the proposed ePAD provided a linear response for standard solutions of ascorbic acid (AA) in the concentration range between 0.1 and 2.0 mmol L. The achieved limit of detection was 4.0 μmol L. As proof of applicability, the ePADs were evaluated for AA analysis in synthetic biofluids (blood plasma and urine), vitamin C tablets, and food (gelatine and orange juice) samples. The analytical parameters of the proposed device were compared with other reports in the literature and exhibited similar or even superior performance, highlighting its feasibility for sensing applications.
本研究描述了一种基于纸的电化学分析装置（ePADs）的开发，该装置使用结合了硅胶和石墨粉的碳基糊剂。ePADs采用丝网印刷技术制造，包括将导电油墨沉积在纸表面的丝网印刷模板上。此外，还设计并3D打印了一种替代电连接器，以使检测方法更便宜、便于携带且可重复。通过扫描电子显微镜（SEM）、拉曼光谱、电化学阻抗谱（EIS）和循环伏安法（CV）测量，对所开发的导电材料的形态、结构和电化学性质进行了研究。考虑到一种知名的氧化还原探针（[Fe(CN)]），结合替代连接器的ePADs显示出高重复性、再现性和稳定的响应。此外，所提出的ePAD对浓度范围在0.1至2.0 mmol/L之间的抗坏血酸（AA）标准溶液提供线性响应。实现的检测限为4.0 μmol/L。作为适用性的证明，对ePADs在合成生物流体（血浆和尿液）、维生素C片和食品（明胶和橙汁）样品中的AA分析进行了评估。将所提出装置的分析参数与文献中的其他报告进行了比较，其表现出相似甚至更优的性能，突出了其在传感应用中的可行性。
