Rosenfeld Tally, Bercovici Moran
Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
Lab Chip. 2014 Dec 7;14(23):4465-74. doi: 10.1039/c4lc00734d. Epub 2014 Sep 26.
We present an experimental and analytical study of a novel paper-based analytical device (μPAD) for isotachophoretic sample focusing. Guided by a simple heat transfer model, we further developed wax printing fabrication to enable the creation of shallow channels, which are critical in providing sufficient dissipation of Joule heat, and thus enable the use of high electric fields and short analysis time. This results in a device that is self-contained on a simple piece of filter paper and does not require any specialized enclosures or cooling devices to combat evaporation at high temperatures. Furthermore, we provide an analytical model for isotachophoretic sample accumulation in porous media, introduce a simple figure of merit for evaluating and comparing the efficiency of such devices, and present experimental validation in both paper and glass channels. Using this device we demonstrate the processing of 30 μL of sample achieving 1000-fold increase in peak concentration in 6 min. We believe that this method and device can serve as a guide to the design of low-cost, rapid and highly sensitive paper-based diagnostic platforms.
我们展示了一种用于等速电泳样品聚焦的新型纸质分析装置（μPAD）的实验和分析研究。在一个简单的传热模型的指导下，我们进一步开发了蜡印制造工艺，以创建浅通道，这对于提供足够的焦耳热耗散至关重要，从而能够使用高电场并缩短分析时间。这使得该装置能够集成在一张简单的滤纸上，并且不需要任何专门的外壳或冷却装置来对抗高温下的蒸发。此外，我们提供了一个用于多孔介质中等速电泳样品积累的分析模型，引入了一个简单的品质因数来评估和比较此类装置的效率，并在纸质和玻璃通道中进行了实验验证。使用该装置，我们展示了对30μL样品的处理，在6分钟内实现了峰值浓度1000倍的增加。我们相信，这种方法和装置可为低成本、快速且高灵敏度的纸质诊断平台的设计提供指导。
