毛细管电泳芯片非接触电导检测系统设计

Design of Contactless Conductivity Detection System for Capillary Electrophoresis Chip

针对毛细管电泳芯片检测系统的微型化,基于ARM11微处理器和嵌入式Linux操作系统,通过自制激励源与信号检测电路,编写驱动程序和上位机软件,设计了一款体积较小的用于毛细管电泳芯片检测的非接触电导检测系统。激励源交流电压频率在10~400 k Hz之间连续可调,电压幅值在0~10 V变化。通过使用电极宽度为1 000μm、电极间距为800μm的电泳芯片对系统进行测试,在频率100 k Hz、10 Vp-p的激励信号下,对浓度为10-3mol/L的氯化钾溶液进行检测,可得到相对峰值大于200 m V的检测信号。

For the capillary electrophoresis chip detection system＇s miniaturization, based on the ARM 11 processor and embedded Linux operating system, by making excitation source and signal detection circuit and writing the driver code and application program, a contacfless conductivity detection system for capillary electrophoresis chip was designed,which has a small volume.The excitation source＇s frequency can be changed from 10 kHz to 400 kHz ,and its amplitude ranged from 0 to 10 V.The width of electrode was 1 000 Ixm and the distance was 800 ixm by using the biochip to test the system.With the AC excitation voltage of 10 Vp-p and 100 kHz,the KCL solution with the density of 10-3 mol/L was detected and a response signal which had a relative peak more than 200 mV was gotten.