检测微量维生素B2的便携式恒电位仪平台设计

摘要

This paper introduced a portable potentiostat platform based on AVR microcontroller,which was used for electrochemical detection of trace vitamin B2.The platform adopted the high-precise conversion chip AD7705 and DAC8831 and used a microcontroller ATmega16 as a controlling core.The integrated operational amplifier was designed by OPA211 as the core device.The software design adopted optimized calibration logic.Therefore,the potentiostat output was effectively controlled,and the functions of setting the potentiostatic and measuring the polarization current parameter were implemented.Testing results showed that the potentiostat potential error was controlled within the millivolt,the maximum error was about 1％,and the test current limit value was less than 1 μA.The stability and sensitivity of the portable potentiostat platform was also analyzed compared with the CHI660C electrochemical instrument.The linearity between the peak current and the concentration of vitamin B2 was measured by the platform experiment,and the correlation coefficient was 0.994.The rapid detection of vitamin B2 in food was preliminarily verified.%设计并实现一种基于AVR单片机的便携式恒电位仪平台,用于食品中微量维生素的电化学检测.采用ATmega16为控制核心,选用AD7705和DAC8831作为转换芯片,集成运放选用OPA211为核心器件,软件优化校准逻辑设计,有效控制恒电位仪误差,实现恒电位设定功能和极化电流参数的测量功能.测试结果表明,恒电位仪的电位误差控制在mV级别,最大误差约1％,测试电流下限达到1μA以内;与CHI660C商用平台进行对照性电学实验,验证该便携式恒电位仪的稳定性及灵敏性;平台应用性实验测得输出峰电流与维生素B2浓度呈线性关系,相关系数为0.994,初步实现对食品中维生素B2的快速检测.