集成恒温和搅拌功能的小型化、高精度电化学传感检测系统的设计与实现

Design and Implementation of Miniaturized and High-Precision Electrochemical Sensing Detection System Integrating Constant Temperature and Stirring Function

出于生化量现场便携检测的目的,同时为了提高传感检测系统的集成度和适用范围,将恒温控制、磁力搅拌和高精度电化学检测相结合,设计了一种小型化、多功能、高精度电化学传感检测系统.系统硬件端采用微控制器搭配信号处理、驱动控制和电源管理等芯片完成电路硬件设计,同时选用微型的电机和加热装置等器件,实现整个检测系统的小型化;软件端不仅在硬件电路中加入操作系统,并且结合上位机程序,实现电化学检测、恒温控制、磁力搅拌、实时显示和数据存储多种功能.电化学检测部分采用低噪声芯片配合后端滤波电路提高了电化学传感检测精度,恒温控制部分加入了比例积分微分算法来提高精度.经过验证,检测系统整体体积为30 cm×30 cm×30 cm,可完成计时电流法、循环伏安法等多种电化学检测功能,电流测量精度可低至0.15 n A,恒温控制精度可达到±0.3℃,搅拌转速精度可达到4%.测量数据验证了所研发的电化学传感检测系统的可靠性和实用性.

For the purpose of on-site portable detection of biochemical quantity,and in order to improve the integration and application scope of the sensing detection system,a miniaturized,multifunctional and high-precision electrochemical sensing detection system is designed by combining constant temperature control,magnetic stirring and high-precision electrochemical detection.At the hardware end of the system,the microcontroller is used with chips such as signal processing,drive control and power management to complete the circuit hardware design.At the same time,micro motors,heating devices and other devices are selected to realize the miniaturization of the whole detection system.The software not only adds the operating system to the hardware circuit,but also combines the host computer program to realize various functions such as electrochemical detection,constant temperature control,magnetic stirring,real-time display and data storage.The electrochemical detection part adopts low-noise chip and back-end filter circuit to improve the detection accuracy of electrochemical sensing,and the constant temperature control part adds proportional integral differential algorithm to improve the accuracy.After verification,the overall volume of the detection system is 30 cm × 30 cm × 30 cm,which can complete various electrochemical detection functions such as chronoamperometry and cyclic voltammetry.The current measurement accuracy can be as low as 0.15 nA,the constant temperature control accuracy can reach ±0.3 ℃,and the stirring speed accuracy can reach 4%.The measured data verify the reliability and practicability of the developed electrochemical sensing detection system.