| Electrochemical technology is an effective analytical method to determine the composition and content of the solution to be tested based on its electrochemical properties.With the advantages of high sensitivity,wide detection range and fast analysis speed,it has an increasing demand for point-of-care testing applications in the fields of medical health,food safety and environmental monitoring.Most current electrochemical detection still requires professional analytical equipment and operators to complete,limiting the widespread use of electrochemical detection technology in point-of-care testing.Therefore,this paper combined the advantages of electrochemical detection and mobile terminal,optimized the circuit design,data transmission and system control,and designed an electrochemical wireless detection device based on mobile terminal.The specific research of this paper will be described in the following aspects:Firstly,the research background of electrochemical technology and the development status of portable electrochemical detection equipment were discussed.The detection principles of electrochemical reactions and electrochemical analysis methods were specifically introduced,and the basic principles of chronoamperometry and cyclic voltammetry and the theoretical basis for quantitative analysis were mainly studied.Secondly,the hardware of the electrochemical detection front-end was designed based on the three-electrode system.The STM32 was used as the control core of the detection front-end,and modularization was adopted to realize the portable design,mainly including power supply circuit module,potentiostatic circuit module,micro-controller module,microcurrent detection module and Bluetooth module.The schematic design and PCB production of the electrochemical detection front-end were final completed.Further,the embedded software of the electrochemical detection front-end and the smartphone-based electrochemical detection APP were designed.The software design in the electrochemical detection front-end was mainly carried out for the potentiostatic circuit module,data transmission protocol,data acquisition and Bluetooth communication module.The software design of the smartphone APP was mainly carried out for the detection parameter setting module,data processing module,image display module and Bluetooth communication module,which realized the data reception,processing and display as well as the detection control of the detection front-end by the smartphone.Finally,experiments were designed to validate the performance of the electrochemical wireless detection device based on mobile terminal,and its feasibility for point-of-care testing was verified by modifying the electrodes to realize the non-enzymatic detection of biomolecules.In the comparative experiment with the electrochemical workstation,the detection error and repeatability of the redox couple were less than 4.20%and 2.92%,respectively,and the goodness of linear fit R~2was higher than 0.9996.In the lactic acid experiment,the lactic acid concentration and the oxidation peak current showed a good linear relationship(R~2=0.9987)after the working electrode was functionalized with Ni O.The repeatability was less than1.14%,and the sensitivity and the detection limit were 7.9268μA/(m M·cm~2)and0.0428m M,respectively.In addition,the detection device has also achieved good detection results in the experiments of uric acid and glucose.In conclusion,the electrochemical wireless detection device based on mobile terminal designed in this paper can accurately perform electrochemical detection and is also expected to be used for the point-of-care testing of biomolecules such as uric acid,glucose and lactic acid. |
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