Jang Ilhoon, Carrão Daniel B, Menger Ruth F, Moraes de Oliveira Anderson R, Henry Charles S
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Institute of Nano Science and Technology, Hanyang University, Seoul 04763, South Korea.
ACS Sens. 2020 Jul 24;5(7):2230-2238. doi: 10.1021/acssensors.0c00937. Epub 2020 Jul 13.
Capillary forces are commonly employed to transport fluids in pump-free microfluidic platforms such as paper-based microfluidics. However, since paper is a porous material consisting of nonuniform cellulose fibers, it has some limitations in performing stable flow functions like mixing. Here, we developed a pump-free microfluidic device that enables rapid mixing by combining paper and plastic. The device was fabricated by laminating transparency film and double-sided adhesive and is composed of an overlapping inlet ending in a paper-based reaction area. The mixing performance of the developed device was confirmed experimentally using aqueous dyes and pH indicators. In addition, the absolute mixing index was evaluated by numerically calculating the concentration field across the microfluidic channels. To demonstrate the utility of the new approach, the detection of an organophosphate pesticide was carried out using a colorimetric enzymatic inhibition assay. The developed device and a smartphone application were used to detect organophosphate pesticide on food samples, demonstrating the potential for onsite analysis.
在诸如纸质微流控等无泵微流控平台中，毛细管力通常用于输送流体。然而，由于纸张是一种由不均匀纤维素纤维组成的多孔材料，在执行诸如混合等稳定流动功能方面存在一些局限性。在此，我们开发了一种通过结合纸张和塑料实现快速混合的无泵微流控装置。该装置通过层压透明薄膜和双面胶制成，由一个重叠的入口和一个基于纸张的反应区域组成。使用水性染料和pH指示剂通过实验证实了所开发装置的混合性能。此外，通过数值计算微流控通道上的浓度场来评估绝对混合指数。为了证明这种新方法的实用性，使用比色酶抑制测定法对有机磷农药进行了检测。所开发的装置和智能手机应用程序用于检测食品样品中的有机磷农药，展示了现场分析的潜力。
