Design Of Portable Potentiostat And Impedance System Based On Electrochemical Parameter Analysis

With the rapid development of microelectronic technology and electrochemical detection technology,potentiostat has been more widely used in routine electrical measurement,qualitative and quantitative analysis of characteristics,three-electrode test system,etc;As the micro-chip processing technology and biosensor technology improves,the biofilm impedance system also plays an increasingly vital role in the detection of the physiological status of cells or bacteria.In the background of the electrochemical parameters of the potentiostat and the impedance system of the status quo,the paper leads the importance of potentiostat in the three-electrode electrochemical that its controlling electrode potential is set to achieve a constant potential pole,which can be used in the rapid detection of trace element.And,the impedance system is applied to the detection process of the attached biofilm,which loads a small applied current or an applied voltage on the cell or the bacteria.The bio-impedance system can be used for detecting the micro-features in the food,Non-invasive detection of the current hindering effect,that is,the impedance of the detection.Therefore,this paper designs and implements a potentiostat and an impedance system based on electrochemical parameter analysis.The main works are as follows:In view of the current market demand for the detection of trace elements in food and electrochemical analysis of potentiostat products are large size,poor control and other issues,combined with modern integrated electronic technology,design and implementation of a microcontroller based on AVR portable potentiostat platform.The platform uses ATmega16 as the control core,the high-precision conversion chip DAC8831 and AD7705 and the integrated operational amplifier chip OPA211,which effectively controls the system error of the micro-potentiostat and realizes the function of constant potential setting and polarization current measurement.The electrochemical performance of the potentiostat was tested by the three-electrode equivalent model.The potential error was controlled to within 5 mV and the lower limit of the test current was 0.1 ?A.And then compared with the CHI660 C commercial experimental platform,the stability and sensitivity of the platform were verified.Aimed at the problems of high cost,large volume and low efficiency of the traditional impedance system with single parameter and existing bio-impedance system,an impedance measurement system based on electrochemical parameter analysis is designed.The system uses a modular portable design to impedance converter AD5933 as the core,through the MSP430 microcontroller as a control unit to achieve the impedance test process automation and real-time display of test results.The impedance and RC network were tested and calibrated in the frequency range of 1 Hz~100 KHz to achieve the accuracy of 1%.According to the comparison experiment with CHI760 E,it was verified that the variance is less than 1 in the case of different diameter electrode,different concentration solution and different kinds of solution.The system was reliable in operation and stable in real-time measuring.The experimental results show that,for the development of portable potentiostat,the concentration of trace vitamin B2 in food can be quantitatively detected and analyzed,at the same time for the impedance system design,the related impedance model analysis can also be carried out.The physiological state of the biofilm was qualitatively and quantitatively evaluated.Therefore,based on the platforms of portable potentiostat micro-vitamin detection and the biofilm-based impedance measurement,it is possible to unite to build the analytical technology of the simultaneous detection of bacteria and micro-analysis of the formation,more rapidly and accurately to detect micro-organisms Growth relevance in different concentrations of vitamin environment.Through the cross-test results of the combined platform,it can be more accuratel to reflect the long-term growth of bacteria under the characteristic environment,and provide services and technical supports for food and public health security.