Measuring the electrophoretic mobility and size of single particles using microfluidic transverse AC electrophoresis (TrACE)
Measuring the electrophoretic mobility and size of single particles using microfluidic transverse AC electrophoresis (TrACE)
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DOI：
10.1039/d3lc00413a
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发表时间：
2023-11-08
期刊：
影响因子：
6.1
通讯作者：
Timperman，Aaron T.
中科院分区：
文献类型：
--
作者：
Choi，M. Hannah;Hong，Liu;Timperman，Aaron T.
测量单个颗粒的电荷和尺寸的能力对于了解颗粒粘附及其与环境的相互作用至关重要。表征生物颗粒（如细胞）的物理特性可以成为研究物理特性变化与疾病发展之间关系的有力工具。目前，通过单个颗粒的电泳迁移率（μep）测量电荷仍然具有挑战性，并且只有一个同时测量μep和尺寸的先前报告。介绍了一种结合粒子跟踪测速技术和交流电泳技术的微流控横向交流电泳技术。在TrACE中，具有0.75至1.5 V振幅的电波横向地施加到整体流，并引起颗粒振荡。PTV记录颗粒的振荡轨迹，因为压力驱动整体流动通过微通道。一个简单的准平衡模型同意与实验测量的频率，振幅和相位，表明粒子运动在很大程度上描述了直流电泳。聚苯乙烯颗粒（直径为0.53、0.84、1和2 μm）的μep测量值与ELS测量值一致，每个颗粒平均100次测量值可提高精度。通过布朗运动同时测量粒度，对于<2 μm的颗粒，通过轨迹量化，对于≥2 μm的颗粒，通过图像分析量化。最后，用B细胞证明了分析完整哺乳动物细胞的能力。预计TrACE系统非常适合作为测量各种单个颗粒的μep和尺寸的现场工具。
The ability to measure the charge and size of single particles is essential to understanding particle adhesion and interaction with their environment. Characterizing the physical properties of biological particles, like cells, can be a powerful tool in studying the association between the changes in physical properties and disease development. Currently, measuring charge via the electrophoretic mobility (μep) of individual particles remains challenging, and there is only one prior report of simultaneously measuring μep and size. We introduce microfluidic transverse AC electrophoresis (TrACE), a novel technique that combines particle tracking velocimetry (PTV) and AC electrophoresis. In TrACE, electric waves with 0.75 to 1.5 V amplitude are applied transversely to the bulk flow and cause the particles to oscillate. PTV records the particles' oscillating trajectories as pressure drives bulk flow through the microchannel. A simple quasi-equilibrium model agrees well with experimental measurements of frequency, amplitude, and phase, indicating that particle motion is largely described by DC electrophoresis. The measured μep of polystyrene particles (0.53, 0.84, 1, and 2 μm diameter) are consistent with ELS measurements, and precision is enhanced by averaging ∼100 measurements per particle. Particle size is simultaneously measured from Brownian motion quantified from the trajectory for particles <2 μm or image analysis for particles ≥2 μm. Lastly, the ability to analyze intact mammalian cells is demonstrated with B cells. TrACE systems are expected to be highly suitable as fieldable tools to measure the μep and size of a broad range of individual particles.