Design Of A Heavy Metal Ion Detection System For Water Based On Electrochemical Sensors

The pollution of heavy metals in natural waters caused by human activities is becoming more and more serious.Although the concentration of these metals is low,due to their long half-life,non-biodegradability and potential to accumulate in different parts of the body,the intake of these metals will have adverse effects on human health.Therefore,rapid,sensitive and accurate detection of heavy metal ions in the environment is very important.Although conventional detection methods have high sensitivity and selectivity,these techniques also have high limitations,including high instrument cost,large equipment volume,complicated sample preparation,and the need for professionals,etc.These limitations make them unsuitable for on-line and continuous Monitoring applications,and do not have the conditions for on-site monitoring.Therefore,the development of simple,fast,and portable new ion detection systems has become a research trend in the future.In this paper,based on the electrochemical detection method as the detection principle,an electrochemical sensor for the detection of heavy metal ions in water was prepared based on screen printing technology,and gold nanoparticles were modified with anodized aluminum oxide(AAO)as a mask to improve the sensor’s performance.Detection performance.Then,the corresponding hardware detection circuit was designed on the basis of differential pulse stripping voltammetry.In addition,a mobile phone APP based on ESP8266 was designed to realize wireless transmission of signals and data visualization.The specific content is as follows:1.Preparation of electrochemical sensors decorated with gold nanoparticles based on screen printing technologyA screen-printed electrode with silver/silver chloride as a reference electrode was prepared on a glass substrate by screen printing technology,and then AAO film was used as a mask to modify the surface of the working electrode with gold nanoparticles.Due to the large specific surface area of gold nanoparticles,and has excellent conductivity,the prepared electrochemical sensor has a significant improvement in the detection performance of heavy metal ions.The linear fitting curve of lead ion is: y=-0.064x-23.7,R2=0.989,and the linear fitting curve of copper ion is y=-1.193x-39.886,R2=0.968.2.Electrochemical hardware detection circuit based on STM32F103This paper takes STM32 as the core,and designs the corresponding hardware detection circuit for the electrochemical sensor.The hardware detection circuit can realize the measurement of differential pulse voltammetry(DPV)and chronoamperometry,and can adjust the initial voltage and the range of termination voltage improves the versatility of the hardware.3.A mobile APP that can identify signal processingThis paper uses the Android mobile phone as a platform to design a mobile phone APP for electrochemical detection.Data processing is simplified,the steps of electrochemical detection are greatly simplified,and it has strong portability.In summary,this paper realizes a heavy metal ion detection system based on electrochemical sensors,which simplifies the procedure of heavy metal ion detection,reduces the cost of detection,and has certain portability.In addition,the designed electrochemical sensor is highly modifiable,broadening its potential application fields.