IEEE Trans Biomed Circuits Syst. 2017 Dec;11(6):1392-1399. doi: 10.1109/TBCAS.2017.2727064. Epub 2017 Aug 4.
Sensitivity is an essential consideration for microfluidic paper-based analytical devices (μPADs) when these devices are used for low concentration sample detection. Very recently, ion concentration polarization (ICP)-based μPADs are emerging as novel tools for bio-sample preconcentration. In this study, we develop an enclosed paper-based microfluidic platform as a preconcentrator based on the ICP effect. This paper chip is fabricated by a Parafilm embedding technique and holds many advantages over traditional open-channel μPADs, which usually suffer from sample contamination and evaporation problems. The enclosed structure minimizes sample evaporation, reduces contamination risk, and increases the mechanical strength of the paper channel. The experiment results show that more than 100-fold concentration enhancement can be achieved in the enclosed paper device, which is comparable with most reported paper-based ICP devices. Additionally, other improved ICP performance has been observed on the enclosed device, including better concentration plug profile, increased concentration durability.
当微流控纸基分析器件 (μPADs) 用于低浓度样品检测时，灵敏度是一个重要的考虑因素。最近，基于离子浓度极化 (ICP) 的 μPADs 作为生物样品预浓缩的新型工具正在出现。在这项研究中，我们开发了一种封闭的基于纸的微流控平台，作为基于 ICP 效应的预浓缩器。这种纸芯片是通过 Parafilm 嵌入技术制造的，与传统的开放式通道 μPADs 相比具有许多优势，传统的开放式通道 μPADs 通常存在样品污染和蒸发问题。封闭结构最大限度地减少了样品蒸发、降低了污染风险，并提高了纸通道的机械强度。实验结果表明，在封闭的纸设备中可以实现超过 100 倍的浓度增强，这与大多数报道的基于纸的 ICP 设备相当。此外，在封闭设备上还观察到了其他改进的 ICP 性能，包括更好的浓度塞轮廓和增加的浓度耐久性。
