快速检测禽流感病毒的生物阻抗测试仪

摘要

在生物芯片上通过测量微(纳)电极阻抗值以诊断溶液中禽流感病毒,是目前禽流感病毒快速检测的方向之一.以AD5933高精度阻抗转换芯片为核心测量芯片,以ATmega16单片机为控制器,通过外围电路设计和调试,研制激励频率范围1～100 kHz、测量阻抗范围1～1 000 kΩ的阻抗测试仪,通过液晶实时显示扫频和定点测量结果.为保证测试仪的准确性,设计了带有35组不同阻抗组合的校正网络,用以实时校正.经精度为0.2％的商品化阻抗测试仪标定,所研制的原理性装置容抗测量精度达3％,通过进一步改进后可以满足使用要求.%The avian influenza virus (AIV) was diagnosed by measuring the impedance of the biological chip's electrodes, which was a development direction of the AIV rapid detection. The high precision impedance conversion chip ( AD5933 ) and the ATmegal6 MCU were used. Through the circuit design and commissioning, an impedance testing instrument with the energizing frequency range of 1 ~100 kHz was developed. The impedance measurement range was 1~1 000 kΩ. This impedance testing instrument has capacity to measure one frequency point and sweep frequency testing. To ensure the accuracy of the instrument, a calibration network with 35 different combinations of impedance was used for providing realtime calibration. The BK866 ( accuracy of 0. 2% ) impedance testing instrument for adjusting the system can make sure that the testing accuracy of captance was above 3%.