Rahmani Ali, Mohammadi Aliasghar, Kalhor Hamid Reza
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran.
Biochemistry Research Laboratory, Department of Chemistry, Sharif University of Technology, Tehran, Iran.
Electrophoresis. 2018 Feb;39(3):445-455. doi: 10.1002/elps.201700166. Epub 2017 Sep 25.
In recent years, applications of dielectrophoresis-based platforms have been recognized as effective and dependable approach to separate cells and bioparticles, suspended in different carrier fluids, based on particle size and electrical properties. In this study, a microfluidic device was fabricated by an unprecedented electrode pattern, and several experiments were performed to enrich samples including either of yeast, Escherichia coli, or latex particles. A chemical deposition-based method was employed for fabrication of microelectrodes, inducing nonuniform electric field required for dielectrophoresis-based separation. One major advantage of our employed method is low fabrication cost, in addition to its accuracy and operation at low voltages. The performance of the microfluidic device in enriching either of injected samples was studied using spectrophotometric techniques. The effects of experimentally controllable parameters (applied-voltage amplitude and frequency, and flow rate) were studied by changing a parameter while keeping the others constant. It became evident that all the aforementioned parameters had modulating impact on the performance of the microfluidic device. Furthermore, to investigate binary interactions among the parameters, response surface methodology was exploited, resulting in a second-order polynomial model for the performance of the device as a function of the parameters. The model was employed for finding the optimum values of the parameters at which the performance of the device is the highest. At optimum values for the experimentally controllable parameters, enrichment efficiencies of 87 ± 2, 82 ± 4, and 86 ± 3% for, respectively, yeast, E. coli, and latex particles were obtained experimentally, confirming the ability of the proposed method for biological and polymeric particles enrichment.
近年来，基于介电泳的平台的应用已被公认为是一种有效且可靠的方法，可根据颗粒大小和电学性质分离悬浮在不同载液中的细胞和生物颗粒。在本研究中，通过一种前所未有的电极图案制造了一种微流控装置，并进行了多项实验以富集包含酵母、大肠杆菌或乳胶颗粒中的任何一种的样品。采用基于化学沉积的方法制造微电极，以诱导基于介电泳分离所需的非均匀电场。我们所采用方法的一个主要优点是制造成本低，此外还具有准确性和低电压操作的特点。使用分光光度技术研究了微流控装置在富集任何一种注入样品方面的性能。通过在保持其他参数不变的情况下改变一个参数，研究了实验可控参数（施加电压幅度和频率以及流速）的影响。很明显，所有上述参数对微流控装置的性能都有调节作用。此外，为了研究参数之间的二元相互作用，采用了响应面方法，得到了一个作为参数函数的装置性能的二阶多项式模型。该模型用于找到装置性能最高时的参数最佳值。在实验可控参数的最佳值下，通过实验分别获得了酵母、大肠杆菌和乳胶颗粒的富集效率为87±2%、82±4%和86±3%，证实了所提出方法用于生物和聚合物颗粒富集的能力。
