Electrochemical paper-based analytical devices (ePADs) are an excellent choice to achieve the goal of global health due to their advantages of low cost, portability, and rapid analysis. However, the low sensitivity limits the application of ePADs. In this study, a 3D origami-inspired ePAD with flow-through electrodes and quasi-steady flow was presented for signal amplification to enhance the sensitivity. A Silhouette Studio plotter/cutter was used to design four schemes with a porous gold electrode as the working electrode. The flow-through electrode with quasi-steady flow exhibited the highest current due to enhanced convective transfer. The peak current of the device combined with flow-through porous electrodes with flow increased by 97.2 and 63.8% compared with the device without flow and the device combined flow-over electrodes with flow, respectively. The finite element simulation results showed that the current increased 10 times compared with the conventional saturated devices with flow-over electrodes and flow-through electrodes. Moreover, the evaluation of the device used copper ions as the detection species. The current of the device that combined flow-through with quasi-steady flow was about twice as large as other schemes and owned higher sensitivity. This strategy provides new insights and a more facile way to amplify signals of ePADs.

中文翻译：

---

具有流通电极和准稳态流的 3D 折纸启发电化学纸基分析装置


电化学纸基分析装置（ePAD）因其低成本、便携、快速分析等优势，成为实现全球健康目标的绝佳选择。然而，低灵敏度限制了ePAD的应用。在这项研究中，提出了一种具有流通电极和准稳态流的 3D 折纸 ePAD，用于信号放大以提高灵敏度。使用 Silhouette Studio 绘图仪/切割机设计了四种方案，以多孔金电极作为工作电极。由于对流传递增强，具有准稳态流动的流通电极表现出最高的电流。流通式多孔电极与流通结合的装置的峰值电流比无流通的装置和流通式电极与流通结合的装置分别增加了97.2%和63.8%。有限元模拟结果表明，与传统的过流电极和流通电极饱和装置相比，电流增加了10倍。此外，该装置的评估使用铜离子作为检测物质。流通式与准稳态流相结合的装置电流大约是其他方案的两倍，并且具有更高的灵敏度。该策略提供了新的见解和更简便的方法来放大 ePAD 信号。