基于介电泳诱捕与阻抗测量的三维网格型生物传感器的研究

摘要

The integration of separation and testing is the bottleneck of micro total analysis system.Based on the combination of dielectrophoresis and impedance measurement, three-dimensional (3D)dieletrophoretic chip was designed. The key structure was three layers that the lower electrodes and upper electrodes sandwich the SU8 photoresis layer. The SU8 photoresis interlayer had the columned trap array. It formed the special distribution of electric field on the ground of 3D array and the SU8 dielectric. The distribution can fall the voltage and the entrapment of the particulate to the trap which is convenient for impedance measurement. Because it is different to the plane electrode that the electric field is dispersive, the chip has higher sensitivity. The switch of the dielectrophoresis and impedance measurement for same electrode has the advantage of easy facture and rapid testing.%微粒分离与检测的集成,一直是微全分析系统亟待解决的难题.结合介电泳与生物阻抗谱测量,设计了一种三维介电泳芯片.以SU8胶为材料的绝缘夹层以及其上方和下方网格状交叉的电极阵列,构成了芯片的关键区域,且在SU8绝缘夹层中利用光刻技术形成了圆柱状小势阱.三维的网格状阵列结构及具有束缚电场功能的SU8电介质,共同形成了其独特的电场极值分布,使得微粒诱捕电压降低的同时,更能将微粒诱捕到SU8阱中,便于阻抗谱测量.三维电极结构解决了平面电极电场分散的难题,具有更高的灵敏度.更为重要的是同一电极的介电泳诱捕与阻抗谱测试的切换使用,降低了制作复杂度,并使测试更加快捷.