芯片介电电泳细胞DEP富集过程研究
|
摘要
基于介电电泳分离原理和微机电加工技术的芯片介电电泳富集操控技术,为生化样品的快速高效富集分离和分析提供了一个有广阔发展前景的技术平台。作为一种非侵入式的细胞操纵技术,芯片介电电泳技术具有高效、高分辨率、低污染以及提取的样本信息多等优点,因此在生化样品分析,尤其是细胞分析中具有相当的重要的研究意义和实用价值。
论文在全面综述国外研究现状的基础上,从介电电泳分离原理和设计制作理论出发,基于四种常规的介电电泳电极构型,探讨不同芯片材料对芯片制作和样品介电电泳过程的影响,选定采用玻璃基片PDMS盖片组成的复合式芯片结构设计模式,进行芯片介电电泳的基础实验过程研究。
给出阵列叉指电极式DEP芯片设计方案,采用Coventorware有限元分析软件对影响样品介电电泳过程的叉指电极表面电场分布、电极间距、介电电泳力作用范围以及施加交流信号电压峰值Vp-p进行模拟优化,最终确定介电电泳芯片结构设计参数和系统集成方案。DEP芯片的具体结构参数为:电极宽度和间距为30μm,管道高度30μm,Vp-p=10V。
采用标准制作工艺完成DEP芯片玻璃基片和SU-8阳膜的制作,并对其进行测试表征,测试结果说明制作的具有阵列叉指电极的玻璃基片和具有微管道的SU-8阳膜符合设计要求,可满足后期细胞样品介电电泳富集分离的需要。在此基础上,以高频低压信号发生系统、CCD显微成像系统和阵列叉指电极式DEP芯片构建了集成介电电泳芯片分析实验系统。
在构建的芯片系统上实现了红细胞和结肠癌细胞的正负DEP富集操控。研究发现,Vp-p是影响DEP富集操控效率的首要因素,Vp-p过小细胞受到的介电电泳力极小,难于实现细胞定位富集,Vp-p过大细胞所受介电电泳力(FDEP)不足以克服其受到交流电渗(Feo),无法实现细胞定位富集,实验选定Vp-p=5V为DEP操控电压;改变交流信号频率f可以改变细胞受介电电泳力的类型,但当频率f≤0.5MHz时,细胞出现水解;细胞在PBS和0.9%NaCl生理盐水两种缓冲溶液中均实现了DEP富集,且其DEP行为存在明显差异。优化后的DEP操作条件为Vp-p=5V,f≤1MHz,缓冲溶液选择0.9%NaCl生理盐水。应用本芯片分析系统富集结肠癌细胞,实验结果表明本系统对结肠癌细胞的正介电电泳富集效率为87.2%,负介电电泳富集效率为84.8%。
Dielectrophoresis on microchip is based on the dielectrophoresis separation principle and Micro Electronic Mechanical System (MEMS) fabrication technique, which is a powerful tool for high efficiency separation and manipulation of biochemical samples. As a non-invasive cell manipulation technique, microchip dielectrophoresis has many advantages, such as high performance, high resolution, low pollution and more samples information. For these reasons, this technique has significant research meaning and potential practical value in biochemical samples analysis, especially in cell analysis.
The developing level of microchip dielectrophoresis in cell analysis was summarized in this paper. Four kinds of simplified dielectrophoresis microchips were designed and manufactured based on the separation principle of dielectrophoresis and the fabrication technology of microchip. Meanwhile, a preliminary study of cell enrichment process was demonstrated on simplified dielectrophoresis microchips. The influence of microchip materials on cell enrichment process and microchip fabrication was discussed, and finally the glass-PDMS composite chip structure was selected and performed chip making.
DEP microchip with interdigitated arrayed electrodes was designed, at the same time, Conventorware finite element analysis software was used to optimize DEP microchip structure parameters and dielectrophoresis enrichment process. The optimum chip structure parameters were the electrode width and interval 30μm, the micro-channel height 30μm, and the optimum DEP manipulation voltage is 10V.
DEP microchip and SU-8 anode film were fabricated using the standard making process. CCD microscopic imaging apparatus and MEMS measuring & operating system were used to characterize electrode dimension, the flatness of glass substrate as well as the depth-width ratio of SU-8 anode film. An integrated dielectrophoresis microchip system was constructed, which was consisted of high-frequency low-voltage signal generating system, DEP microchip with interdigitated arrayed electrodes and CCD microscope imaging detection system.
Different types DEP positioning enrichment of the red blood cells and colon cancer cells were achieved on the constructed system. The dielectrophoresis enrichment and manipulation parameters were optimized according to the peak value of applied AC signal and its frequency, as well as the type and composition of buffer solution. With the optimized operation parameters of the AC signal peak value was set to 5V, the frequency of AC signal range from 20MHz to 1MHz. The study demonstrated that enrichment efficiency of DEP was controlled by the AC signal peak value and the types of dielectrophoresis were determined by the frequency of AC signal and composition of buffer solution. Enrichment efficiency of positive and negative DEP to colon cancer cells respectively reached 87.2% and 84.8% on the constructed system.
论文在全面综述国外研究现状的基础上,从介电电泳分离原理和设计制作理论出发,基于四种常规的介电电泳电极构型,探讨不同芯片材料对芯片制作和样品介电电泳过程的影响,选定采用玻璃基片PDMS盖片组成的复合式芯片结构设计模式,进行芯片介电电泳的基础实验过程研究。
给出阵列叉指电极式DEP芯片设计方案,采用Coventorware有限元分析软件对影响样品介电电泳过程的叉指电极表面电场分布、电极间距、介电电泳力作用范围以及施加交流信号电压峰值Vp-p进行模拟优化,最终确定介电电泳芯片结构设计参数和系统集成方案。DEP芯片的具体结构参数为:电极宽度和间距为30μm,管道高度30μm,Vp-p=10V。
采用标准制作工艺完成DEP芯片玻璃基片和SU-8阳膜的制作,并对其进行测试表征,测试结果说明制作的具有阵列叉指电极的玻璃基片和具有微管道的SU-8阳膜符合设计要求,可满足后期细胞样品介电电泳富集分离的需要。在此基础上,以高频低压信号发生系统、CCD显微成像系统和阵列叉指电极式DEP芯片构建了集成介电电泳芯片分析实验系统。
在构建的芯片系统上实现了红细胞和结肠癌细胞的正负DEP富集操控。研究发现,Vp-p是影响DEP富集操控效率的首要因素,Vp-p过小细胞受到的介电电泳力极小,难于实现细胞定位富集,Vp-p过大细胞所受介电电泳力(FDEP)不足以克服其受到交流电渗(Feo),无法实现细胞定位富集,实验选定Vp-p=5V为DEP操控电压;改变交流信号频率f可以改变细胞受介电电泳力的类型,但当频率f≤0.5MHz时,细胞出现水解;细胞在PBS和0.9%NaCl生理盐水两种缓冲溶液中均实现了DEP富集,且其DEP行为存在明显差异。优化后的DEP操作条件为Vp-p=5V,f≤1MHz,缓冲溶液选择0.9%NaCl生理盐水。应用本芯片分析系统富集结肠癌细胞,实验结果表明本系统对结肠癌细胞的正介电电泳富集效率为87.2%,负介电电泳富集效率为84.8%。
Dielectrophoresis on microchip is based on the dielectrophoresis separation principle and Micro Electronic Mechanical System (MEMS) fabrication technique, which is a powerful tool for high efficiency separation and manipulation of biochemical samples. As a non-invasive cell manipulation technique, microchip dielectrophoresis has many advantages, such as high performance, high resolution, low pollution and more samples information. For these reasons, this technique has significant research meaning and potential practical value in biochemical samples analysis, especially in cell analysis.
The developing level of microchip dielectrophoresis in cell analysis was summarized in this paper. Four kinds of simplified dielectrophoresis microchips were designed and manufactured based on the separation principle of dielectrophoresis and the fabrication technology of microchip. Meanwhile, a preliminary study of cell enrichment process was demonstrated on simplified dielectrophoresis microchips. The influence of microchip materials on cell enrichment process and microchip fabrication was discussed, and finally the glass-PDMS composite chip structure was selected and performed chip making.
DEP microchip with interdigitated arrayed electrodes was designed, at the same time, Conventorware finite element analysis software was used to optimize DEP microchip structure parameters and dielectrophoresis enrichment process. The optimum chip structure parameters were the electrode width and interval 30μm, the micro-channel height 30μm, and the optimum DEP manipulation voltage is 10V.
DEP microchip and SU-8 anode film were fabricated using the standard making process. CCD microscopic imaging apparatus and MEMS measuring & operating system were used to characterize electrode dimension, the flatness of glass substrate as well as the depth-width ratio of SU-8 anode film. An integrated dielectrophoresis microchip system was constructed, which was consisted of high-frequency low-voltage signal generating system, DEP microchip with interdigitated arrayed electrodes and CCD microscope imaging detection system.
Different types DEP positioning enrichment of the red blood cells and colon cancer cells were achieved on the constructed system. The dielectrophoresis enrichment and manipulation parameters were optimized according to the peak value of applied AC signal and its frequency, as well as the type and composition of buffer solution. With the optimized operation parameters of the AC signal peak value was set to 5V, the frequency of AC signal range from 20MHz to 1MHz. The study demonstrated that enrichment efficiency of DEP was controlled by the AC signal peak value and the types of dielectrophoresis were determined by the frequency of AC signal and composition of buffer solution. Enrichment efficiency of positive and negative DEP to colon cancer cells respectively reached 87.2% and 84.8% on the constructed system.
引文
[1] Huang Y, Joo S, Duhon M, et al. Dielectrophoretic Cell Separation and Gene Expression Profiling on Microelectronic Chip Arrays[J]. Anal. Chem., 2002, 74(14):3362-3371.
[2] Rajaraman S, Noh H S, Hesketh P J, et al. Rapid, low cost microfabrication technologies toward realization of devices for dielectrophoretic manipulation of particles and nanowires[J]. Sensors and Actuators B, 2006, 114(1):392-401.
[3] Mihai L, Separation of small metallic nonferrous particles in low concentration from mineral wastes using dielectrophoresis[J], Int. J. Miner. Process. 2006, 78: 215–219.
[4] Park B Y, Madou M J, 3-D electrode designs for flow-through dielectrophoretic systems[J], Electrophoresis 2005, 26: 3745–3757.
[5] Cui L, Holmes D, Morgan H, The dielectrophoretic levitation and separation of latex beads in microchips[J], Electrophoresis 2001, 22: 3893–3901.
[6] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectroresis[J], Electrophoresis 2001, 22: 283–288.
[7] Yasukawa T, Suzuki M, Sekiya T, et al. Flow sandwich-type immunoassay in microfluidic devices based on negative dielectrophoresis[J], Biosensors and Bioelectronics 2007,22: 2730–2736.
[8] Lapizco-Encinas B H, Davalos R V, Simmons B A, An insulator-based (electrodeless) dielectrophoretic concentratorfor microbes in water[J], Journal of Microbiological Methods 2005, 62: 317– 326.
[9] Castellarnau M, Zine N, Bausells J, et al. Integrated cell positioning and cell-based ISFET biosensors[J]. Sensors and Actuators B, 2007, 120(2): 615-620.
[10] Xu C X, Wang Y, Cao M, et al. Dielectrophoresis of human red cells in microchips[J]. Electrophoresis, 1999, 20(9):1829-1831.
[11] Ramadana Q, Samper V, Poenar D, et al. Simultaneous cell lysis and bead trapping in a continuous flow microfluidic device, Sensors and Actuators B 2006, 113: 944–955.
[12] Arnold W M, Franich N R, Cell isolation and growth in electric-field defined micro-wells, Current Applied Physics 2006,6: 371–374.
[13] Li H B, Bashir R. Dielectrophrotic sepatation and manipulation of live and heat-treated cells of Listeria on microfbricated devices with interdigitated electrodes[J], Sensors and Actuators B, 2002, 86(2-3):215-221.
[14] Zhou H, White L R, Tilton R D, Lateral separation of colloids or cells by dielectrophoresisaugmented by AC electroosmosis[J], Journal of Colloid and Interface Science 2005, 285: 179–191.
[15] Pethig R, Biodetection using micro-physimetry tools based on electrokinetic phenomena[J], Implementation Strategies and Commercial Opportunities, 2005, 129–142.
[16] Abidin Z Z, Markx G H, High-gradient electric field system for the dielectrophoretic separation of cells[J], Journal of Electrostatics 2005,63: 823–830.
[17] Ho C T, Lin R Z, Chang W Y, et al. Rapid heterogeneous liver-cell on-chip patterning via the enhanced field-induced dielectrophoresis trap[J]. Lab Chip, 2006, 6: 724-734.
[18] Luo C P, Andreas H, Wolfgang H, et al. Nanoelectrode arrays for on-chip manipulation of biomolecules in aqueous solutions[J]. Microelectronic Engineering, 2006, 83:1634-1637.
[19] Cheng J, Sheldon E L, Wu L, et al. Isolation of Cultured Cervical Carcinoma Cells Mixed with Peripheral Blood Cells on a Bioelectronic Chip[J]. Anal. Chem., 1998, 70 (11): 2321-2326.
[20] Doh I, Cho Y-H. A continuous cell separation chip using hydrodynamic dielectrophoresis (DEP) process[J]. Sensors and Actuators A, 2005, 121(1): 59-65.
[21] Suehiro J, Ohtsubo A, Hatano T, et al. Selective detection of bacteria by a dielectrophoretic impedance measurement method using an antibody-immobilized electrode chip[J]. Sensors and Actuators B, 2006, 119(1):319-326.
[22] Yang L, Banada P P, Chatni M R, et al. A multifunctional micro-fluidic system for dielectrophoretic concentration coupled with immuno-capture of low numbers of Listeria monocytogenes[J]. Lab Chip, 2006, 6: 896-905.
[23] Gadish N, Voldman J. High-Throughput positive-Dielectrophoretic Bioparticle Microconcentrator[J]. Anal. Chem., 2006, 78 (22): 7870-7876.
[24] Li Y L, Dalton C, Crabtree H J, et al. Continuous dielectrophoretic cell separation microfluidic device[J]. Lab Chip, 2007, 7:239-248.
[25] Cummings E B, Singh A K. Dielectrophoresis in Microchips Containing Arrays of Insulating Posts: Theoretical and Experimental Results[J]. Anal. Chem., 2003, 75(18): 4724-4731.
[26] Lapizco-Encinas B H, Simmons B A, Cummings, E B, Fintschenko Y. Dielectrophoretic Concentration and Separation of Live and Dead Bacteria in an Array of Insulators[J]. Anal. Chem., 2004, 76(6): 1571-1579.
[27] Lapizco-Encinas B H, Simmons B A, Cummings E B. Insulator-based dielectrophoresis for the selective concentration and separation of live bacteria in Water[J], Electrophoresis, 2004, 25(10-11): 1695-1704.
[28] Kang K H, Kang Y J, Xuan H C. Continuous separation of microparticles by size with Directcurrent-dielectrophoresis[J], Electrophoresis, 2006, 27(3): 694-702.
[29] Barbulovic-Nad I, Xuan X, Lee J S H, et al. DC-dielectrophoretic separation of microparticles using an oil droplet obstacle[J]. Lab Chip, 2006, 6:274-279.
[30] Morishimaa K, Araia F, Fukudab T, et al. Screening of single Escherichia coli in a microchannel system by electric field and laser tweezers[J]. Analytica Chimica Acta, 1998, 365:273-278.
[31] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectroresis[J]. Electrophoresis, 2001,22(2):283-288.
[32] Cui L, Holmes D, Morgan H. The dielectrophoretic levitation and separation of latex beads in microchips[J]. Electrophoresis, 2001, 22(18):3893-3901.
[33] Taff B M, Voldman J. A Scalable Addressable Positive-Dielectrophoretic Cell-Sorting Array[J]. Anal. Chem., 2005, 77 (24): 7976 -7983.
[34] Cheung K, Gawad S, Renaud P, Impedance Spectroscopy Flow Cytometry: On-Chip Label-Free Cell Differentiation[J], Cytometry Part A 2005, 65A: 124-132.
[35] Yasukawa T, Suzuki M, Sekiya T, Flow sandwich-type immunoassay in microfluidic devices based on negative dielectrophoresis[J], Biosens. Bioelectron. 2006, 22 (11): 2730–2736.
[36] Park B Y, Madou M J, 3-D electrode designs for flow-through dielectrophoretic systems[J], Electrophoresis 2005, 26: 3745–3757.
[37] Hayashi K, Iwasaki Y, Kurita R, The highly sensitive detection of catecholamines using a micro?uidic device integrated with an enzyme-modified pre-reactor for interferent elimination and an interdigitated array electrode[J], Journal of Electroanalytical Chemistry 2005, 579: 215–222.
[38] Kang K H, Li D Q, Force acting on a dielectric particle in a concentration gradient by ionic concentration polarization under an externally applied DC electric field[J], Journal of Colloid and Interface Science, 2005, 286: 792–806.
[39] Garlos F G, Vincent T R, Harnessing dielectric forces for separations of cells, fine particles and macromolecules[J], Journal of Chromatography A, 2005, 1079: 59-68.
[40] Minerick A R, Zhou R H, Manipulation and characterization of red blood cells with alternating current fields in microdevices[J], Electrophoresis 2003, 24, 3703–3717.
[41] Leu T S, Chen H Y, Hsiao F B, Studies of particle holding, separating, and focusing using convergent electrodes in microsorters[J], Micro?uid Nano?uid 2005, 1: 328–335.
[42] Xu C X, Wang Y, Cao M, et al. Dielectrophoresis of human red cells in microchips[J], Electrophoresis 1999, 20: 1829-1831.
[43] Liu X M, Spencer J L, Kaiser A B, et al. Selective purification of multiwalled carbon nanotubes by dielectrophoresis within a large array[J], Current Applied Physics, 2006, 6: 427–431.
[44] LuY S, Huang Y P, Yeh J A, et al. Controllability of non-contact cell manipulation by image dielectrophoresis (iDEP)[J], Optical and Quantum Electronics, 2005, 37: 1385–1395.
[45] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectrophoresis[J], Electrophoresis, 2001, 22: 283-286.
[46] Li H B, Rashid B, On the Design and Optimization of Micro-Fluidic Dielectrophoretic Devices: A Dynamic Simulation Study[J], Biomedical Microdevices, 2004, 6 (4): 289–295.
[47] http://www.emfhealth.com/211.php?/211/viewtopic.php?t=245&view=unread.
[48]司徒镇强,吴军正.细胞培养[M],西安:世界图书出版社, 2004: 73-74.
[49] Asbury C L, Diercks A H, Engh G, Trapping of DNA by dielectrophoresis, Electrophoresis, 2002, 23: 2658–2666.
[50] Christensen T B, Pedersen C M, Bang D D, et al. Sample preparation by cell guiding using negative dielectrophoresis[J]. Microelectronic Engineering, 2007, 84:1690-1693.
[2] Rajaraman S, Noh H S, Hesketh P J, et al. Rapid, low cost microfabrication technologies toward realization of devices for dielectrophoretic manipulation of particles and nanowires[J]. Sensors and Actuators B, 2006, 114(1):392-401.
[3] Mihai L, Separation of small metallic nonferrous particles in low concentration from mineral wastes using dielectrophoresis[J], Int. J. Miner. Process. 2006, 78: 215–219.
[4] Park B Y, Madou M J, 3-D electrode designs for flow-through dielectrophoretic systems[J], Electrophoresis 2005, 26: 3745–3757.
[5] Cui L, Holmes D, Morgan H, The dielectrophoretic levitation and separation of latex beads in microchips[J], Electrophoresis 2001, 22: 3893–3901.
[6] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectroresis[J], Electrophoresis 2001, 22: 283–288.
[7] Yasukawa T, Suzuki M, Sekiya T, et al. Flow sandwich-type immunoassay in microfluidic devices based on negative dielectrophoresis[J], Biosensors and Bioelectronics 2007,22: 2730–2736.
[8] Lapizco-Encinas B H, Davalos R V, Simmons B A, An insulator-based (electrodeless) dielectrophoretic concentratorfor microbes in water[J], Journal of Microbiological Methods 2005, 62: 317– 326.
[9] Castellarnau M, Zine N, Bausells J, et al. Integrated cell positioning and cell-based ISFET biosensors[J]. Sensors and Actuators B, 2007, 120(2): 615-620.
[10] Xu C X, Wang Y, Cao M, et al. Dielectrophoresis of human red cells in microchips[J]. Electrophoresis, 1999, 20(9):1829-1831.
[11] Ramadana Q, Samper V, Poenar D, et al. Simultaneous cell lysis and bead trapping in a continuous flow microfluidic device, Sensors and Actuators B 2006, 113: 944–955.
[12] Arnold W M, Franich N R, Cell isolation and growth in electric-field defined micro-wells, Current Applied Physics 2006,6: 371–374.
[13] Li H B, Bashir R. Dielectrophrotic sepatation and manipulation of live and heat-treated cells of Listeria on microfbricated devices with interdigitated electrodes[J], Sensors and Actuators B, 2002, 86(2-3):215-221.
[14] Zhou H, White L R, Tilton R D, Lateral separation of colloids or cells by dielectrophoresisaugmented by AC electroosmosis[J], Journal of Colloid and Interface Science 2005, 285: 179–191.
[15] Pethig R, Biodetection using micro-physimetry tools based on electrokinetic phenomena[J], Implementation Strategies and Commercial Opportunities, 2005, 129–142.
[16] Abidin Z Z, Markx G H, High-gradient electric field system for the dielectrophoretic separation of cells[J], Journal of Electrostatics 2005,63: 823–830.
[17] Ho C T, Lin R Z, Chang W Y, et al. Rapid heterogeneous liver-cell on-chip patterning via the enhanced field-induced dielectrophoresis trap[J]. Lab Chip, 2006, 6: 724-734.
[18] Luo C P, Andreas H, Wolfgang H, et al. Nanoelectrode arrays for on-chip manipulation of biomolecules in aqueous solutions[J]. Microelectronic Engineering, 2006, 83:1634-1637.
[19] Cheng J, Sheldon E L, Wu L, et al. Isolation of Cultured Cervical Carcinoma Cells Mixed with Peripheral Blood Cells on a Bioelectronic Chip[J]. Anal. Chem., 1998, 70 (11): 2321-2326.
[20] Doh I, Cho Y-H. A continuous cell separation chip using hydrodynamic dielectrophoresis (DEP) process[J]. Sensors and Actuators A, 2005, 121(1): 59-65.
[21] Suehiro J, Ohtsubo A, Hatano T, et al. Selective detection of bacteria by a dielectrophoretic impedance measurement method using an antibody-immobilized electrode chip[J]. Sensors and Actuators B, 2006, 119(1):319-326.
[22] Yang L, Banada P P, Chatni M R, et al. A multifunctional micro-fluidic system for dielectrophoretic concentration coupled with immuno-capture of low numbers of Listeria monocytogenes[J]. Lab Chip, 2006, 6: 896-905.
[23] Gadish N, Voldman J. High-Throughput positive-Dielectrophoretic Bioparticle Microconcentrator[J]. Anal. Chem., 2006, 78 (22): 7870-7876.
[24] Li Y L, Dalton C, Crabtree H J, et al. Continuous dielectrophoretic cell separation microfluidic device[J]. Lab Chip, 2007, 7:239-248.
[25] Cummings E B, Singh A K. Dielectrophoresis in Microchips Containing Arrays of Insulating Posts: Theoretical and Experimental Results[J]. Anal. Chem., 2003, 75(18): 4724-4731.
[26] Lapizco-Encinas B H, Simmons B A, Cummings, E B, Fintschenko Y. Dielectrophoretic Concentration and Separation of Live and Dead Bacteria in an Array of Insulators[J]. Anal. Chem., 2004, 76(6): 1571-1579.
[27] Lapizco-Encinas B H, Simmons B A, Cummings E B. Insulator-based dielectrophoresis for the selective concentration and separation of live bacteria in Water[J], Electrophoresis, 2004, 25(10-11): 1695-1704.
[28] Kang K H, Kang Y J, Xuan H C. Continuous separation of microparticles by size with Directcurrent-dielectrophoresis[J], Electrophoresis, 2006, 27(3): 694-702.
[29] Barbulovic-Nad I, Xuan X, Lee J S H, et al. DC-dielectrophoretic separation of microparticles using an oil droplet obstacle[J]. Lab Chip, 2006, 6:274-279.
[30] Morishimaa K, Araia F, Fukudab T, et al. Screening of single Escherichia coli in a microchannel system by electric field and laser tweezers[J]. Analytica Chimica Acta, 1998, 365:273-278.
[31] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectroresis[J]. Electrophoresis, 2001,22(2):283-288.
[32] Cui L, Holmes D, Morgan H. The dielectrophoretic levitation and separation of latex beads in microchips[J]. Electrophoresis, 2001, 22(18):3893-3901.
[33] Taff B M, Voldman J. A Scalable Addressable Positive-Dielectrophoretic Cell-Sorting Array[J]. Anal. Chem., 2005, 77 (24): 7976 -7983.
[34] Cheung K, Gawad S, Renaud P, Impedance Spectroscopy Flow Cytometry: On-Chip Label-Free Cell Differentiation[J], Cytometry Part A 2005, 65A: 124-132.
[35] Yasukawa T, Suzuki M, Sekiya T, Flow sandwich-type immunoassay in microfluidic devices based on negative dielectrophoresis[J], Biosens. Bioelectron. 2006, 22 (11): 2730–2736.
[36] Park B Y, Madou M J, 3-D electrode designs for flow-through dielectrophoretic systems[J], Electrophoresis 2005, 26: 3745–3757.
[37] Hayashi K, Iwasaki Y, Kurita R, The highly sensitive detection of catecholamines using a micro?uidic device integrated with an enzyme-modified pre-reactor for interferent elimination and an interdigitated array electrode[J], Journal of Electroanalytical Chemistry 2005, 579: 215–222.
[38] Kang K H, Li D Q, Force acting on a dielectric particle in a concentration gradient by ionic concentration polarization under an externally applied DC electric field[J], Journal of Colloid and Interface Science, 2005, 286: 792–806.
[39] Garlos F G, Vincent T R, Harnessing dielectric forces for separations of cells, fine particles and macromolecules[J], Journal of Chromatography A, 2005, 1079: 59-68.
[40] Minerick A R, Zhou R H, Manipulation and characterization of red blood cells with alternating current fields in microdevices[J], Electrophoresis 2003, 24, 3703–3717.
[41] Leu T S, Chen H Y, Hsiao F B, Studies of particle holding, separating, and focusing using convergent electrodes in microsorters[J], Micro?uid Nano?uid 2005, 1: 328–335.
[42] Xu C X, Wang Y, Cao M, et al. Dielectrophoresis of human red cells in microchips[J], Electrophoresis 1999, 20: 1829-1831.
[43] Liu X M, Spencer J L, Kaiser A B, et al. Selective purification of multiwalled carbon nanotubes by dielectrophoresis within a large array[J], Current Applied Physics, 2006, 6: 427–431.
[44] LuY S, Huang Y P, Yeh J A, et al. Controllability of non-contact cell manipulation by image dielectrophoresis (iDEP)[J], Optical and Quantum Electronics, 2005, 37: 1385–1395.
[45] Arai F, Ichikawa A, Ogawa M, et al. High-speed separation system of randomly suspended single living cells by laser trap and dielectrophoresis[J], Electrophoresis, 2001, 22: 283-286.
[46] Li H B, Rashid B, On the Design and Optimization of Micro-Fluidic Dielectrophoretic Devices: A Dynamic Simulation Study[J], Biomedical Microdevices, 2004, 6 (4): 289–295.
[47] http://www.emfhealth.com/211.php?/211/viewtopic.php?t=245&view=unread.
[48]司徒镇强,吴军正.细胞培养[M],西安:世界图书出版社, 2004: 73-74.
[49] Asbury C L, Diercks A H, Engh G, Trapping of DNA by dielectrophoresis, Electrophoresis, 2002, 23: 2658–2666.
[50] Christensen T B, Pedersen C M, Bang D D, et al. Sample preparation by cell guiding using negative dielectrophoresis[J]. Microelectronic Engineering, 2007, 84:1690-1693.