Simultaneous Determination of Linear and Nonlinear Electrophoretic Mobilities of Cells and Microparticles
Simultaneous Determination of Linear and Nonlinear Electrophoretic Mobilities of Cells and Microparticles
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DOI：
10.1021/acs.analchem.0c03525
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发表时间：
2020-11-17
影响因子：
7.4
通讯作者：
Lapizco-Encinas, Blanca H.
中科院分区：
文献类型：
--
作者：
Antunez-Vela, Sofia;Perez-Gonzalez, Victor H.;Lapizco-Encinas, Blanca H.
基于直流绝缘体的电动力学（DC-iEK）是微流体的分支，其已被证明是用于操纵微米和纳米颗粒（包括微生物）的有吸引力且有效的技术。DC-iEK设备的一个独特特征是非线性EK效应通过绝缘结构之间的较高场强区域的存在而增强。精确的计算模型，描述粒子和细胞的行为，是至关重要的优化设计和提高DC-iEK设备的性能。电动平衡条件（E-EEC）是最近引入的基本概念，它从根本上改变了这些微流体装置中粒子操纵分析背后的观点。E-EEC考虑了以前忽略的对粒子迁移的非线性效应，并表明这些效应是控制DC-iEK设备中粒子运动的核心。在这项研究中，我们提出了一个同时实验表征的线性和非线性电动力学（EK）参数，即电泳迁移率（μ（（1））（EP）），粒子zeta电位（zeta（P）），E-EEC，和第二类电泳迁移率（μ（（3））（EP），为四种类型的聚苯乙烯微粒和四种细胞株。为此，我们研究了聚苯乙烯微粒的电迁移，其尺寸范围从2 μ m到6.8 μ m，三种细菌菌株（B.蜡样E. coli和S. enterica）和酵母细胞（S.酿酒酵母），尺寸范围从1到6.3 μ m，在具有矩形横截面的聚二甲基硅氧烷（PDMS）微流体通道中。结果表明，电动粒子捕获可以发生线性和非线性电泳和电渗达到平衡，没有绝缘柱的存在。本文报道的实验测量参数将允许优化未来DC-iEK器件的设计，以用于广泛的应用（例如，分离多种粒子和微生物），以及开发更好地代表现实的计算模型。
Direct-current insulator-based electrokinetics (DC-iEK) is a branch of microfluidics that has demonstrated to be an attractive and efficient technique for manipulating micro- and nano- particles, including microorganisms. A unique feature of DC-iEK devices is that nonlinear EK effects are enhanced by the presence of regions of higher field intensity between the insulating structures. Accurate computational models, describing particle and cell behavior, are crucial to optimize the design and improve the performance of DC-iEK devices. The electrokinetic equilibrium condition (E-EEC) is a recently introduced fundamental concept that has radically shifted the perspective behind the analysis of particle manipulation in these microfluidic devices. The E-EEC takes into consideration previously neglected nonlinear effects on particle migration and indicates that these effects are central to control particle motion in DC-iEK devices. In this study, we present a simultaneous experimental characterization of linear and nonlinear electrokinetic (EK) parameters, that is, the electrophoretic mobility (mu((1))(EP)), the particle zeta potential (zeta(P)), the E-EEC, and the electrophoretic mobility of the second kind (mu((3))(EP)), for four types of polystyrene microparticles and four cell strains. For this, we studied the electromigration of polystyrene microparticles ranging in size from 2 to 6.8 mu m, three bacteria strains (B. cereus, E. coli, and S. enterica) and a yeast cell (S. cerevisiae), ranging in size from 1 to 6.3 mu m, in a polydimethylsiloxane (PDMS) microfluidic channel with a rectangular cross-section. The results illustrated that electrokinetic particle trapping can occur by linear and nonlinear electrophoresis and electroosmosis reaching an equilibrium, without the presence of insulating posts. The experimentally measured parameters reported herein will allow optimizing the design of future DC-iEK devices for a wide range of applications (e.g., to separate multiple kinds of particles and microorganisms) and for developing computational models that better represent reality.