紙基微流道分析裝置正迅速地發展，提供一個低成本及操作簡單檢測或診斷機制，使人們的生活更加豐富及便利。然而，結合離子濃度極化理論於紙基晶片上的應用或分析卻很少於文獻中提及。在這篇論文中，我們用一個簡易的實驗說明了電滲流可以發生在紙張上。接著，我們第一個在有塗上Nafion的紙張上量測電流-電壓曲線，而此舉更直接驗證了離子濃度極化(ICP)現象的發生。我們也用掃描電子顯微鏡(SEM)的影像來說明Nafion確實可以填滿紙張的孔隙。此外，我們不只更進一步地在紙基晶片中用電動力學的概念驗證了樣品預濃縮的可行性，也找出一個有能力更加提升預濃縮濃度的漸縮管道。而我們也找到了在我們的裝置中之最佳漸縮管道，施加電壓50伏特130秒的情況下，最佳漸縮管道能將螢光粒(fluorescein)從初始濃度10µM濃縮20倍。樣品的需求量只要2µL，這種優勢能提供一個檢測平台給少量樣品的情況。此外，我們也提到了如何改善濃縮樣品之消散現象。樣品濃縮後的最高濃度有能力多維持10到20秒，並且可以被維持在差不多的區域。最後，為了證明這種方法的實用性，我們以結合著FITC螢光粒子的牛血清白蛋白(FITC-BSA)驗證稀薄溶液中的蛋白質也能在紙基晶片上被預濃縮，且能在施加電壓50伏特120秒的情況下，從初始濃度10µM濃縮15倍。這種方法能達到點對點照護(point-of-care)的目標，尤其是對於開發中國家或資源缺乏的地區。

Microfluidic paper-based analytical devices (µPADs) are rapidly developed to enable low-cost and easy diagnostics for improving human life. However, there is still rare analysis and application of ion concentration polarization (ICP) in a µPAD. In this thesis, we use a facile experiment to demonstrate that the electroosmotic flow can take place on a µPAD. Moreover, we are the first to measure the current-voltage curve of a Nafion-coated µPAD, demonstrating that ICP is occurring. In addition, we also use Scanning-electron microscope (SEM) to show the Nafion can fill the pores of paper, providing ion-selective nano-junctions to the µPADs. Furthermore, we not only electrokinetically demonstrate the feasibility of the sample preconcentration method in µPADs but also design a convergent channel that has ability to enhance the focused concentration. An optimal convergent channel in our devices was also obtained and it can reach a 20-fold improvement of fluorescein concentration from the initial concentration of 10µM within 130 s under 50 V. The sample volume required is only 2µL, and thereby providing a platform for the low-volume detections. Improving the dispersion problem of the concentrated molecules is also discussed. The highest concentration of the sample plug can be retained at the same location for an additional 10 to 20 s. Finally, we also use fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) for demonstrating that proteins in diluted solution can be concentrated by a factor of 15 from the initial concentration of 10µM within 120 s under the application of 50 V on µPADs for practical applications, which can reach the goal of point-of-care (POC) benefiting human life, especially for developing countries and resource-poor settings.

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