研制了一种集成于硅基电泳芯片分离沟道末端侧壁的新型二电极非接触电导检测器.讨论了影响电导检测响应灵敏度的相关因素;采用MEMS分析软件及等效电路模拟仿真,确定了检测器的相关参数,电极长度为550μm,宽度为15μm,间距为80μm,绝缘层厚度为1μm,电导检测工作频率为300 kHz.在加工技术中,选用SOI(sili-con on insulator)基片制作十字形微沟道及集成电导检测电极,采用深刻蚀和隔离技术使检测电极被完全隔离成孤岛,利用硼掺杂技术在分离沟道末端侧壁形成立体电极,获得了集成非接触电导检测电极的硅基电泳芯片.在外加Vpp为10 V、工作频率为300 kHz的正弦波激励下,进行了Na+无机阳离子浓度梯度实验以及Na+和Li+混合无机阳离子的电泳分离检测.结果表明,Na+浓度在1×10-9~1×10-4 mol/L范围内,电导响应信号随着离子浓度的增加而增大,检出限达到1×10-9 mol/L;Na+和Li+混合无机阳离子的分离度达到2.0,实现基线分离.
A novel contactless conductivity detector with two electrodes integrated along the sidewalls of the ending separation channel of silicon-based electrophoresis microchip was presented in this paper,and factors influencing the response sensitivity of conductivity detection were discussed.Parameters of the detector were determined by MEMS analysis software and the equivalent circuit simulation,including electrode length of 550 μm,width of 15 μm,distance of 80 μm,thickness of insulation layer of 1 μm and conduc...