Research On Composite Polyaniline Electrochemical Sensor For Heavy Metal Ion Detection

Nowadays people care more about the quality of their life,so there is a growing demand for convenient and rapid analytical instruments in the fields of environmental detection,daily life and medical treatment.The content of copper ions,lead ions and mercury ions is closely related to many diseases.Therefore,it is very important to construct a sensor that is convenient,fast,sensitive,efficient,and capable of detecting these substances in real time.In this paper,the conductive ink of polyaniline（PANI）and its nanocomposites was prepared by chemical synthesis method.Using polyaniline（PANI）as the electrode active material,the screen printed carbon electrode（SPCE）was modified to construct a flexible disposable electrochemical sensor,and three kinds of ions of copper,lead and mercury were successfully tested and analyzed.The specific work content is as follows:1.This work is the first to propose the use of electronic ink technology to prepare polyaniline nanowires functional ink.PANI and EDTA@PANI/MWCNTs were used as the electrode active materials to modify the screen printed electrode（SPCE）,and the electrochemical sensor electrodes of PANI and EDTA@PANI/MWCNTs were constructed.The modified materials were characterized by transmission electron microscope（TEM）,scanning electron microscope（SEM）and the Fourier infrared spectrometer（FTIR）.2.Using PANI modified screen printing electrode and through square wave stripping voltammetry（SWV）,The copper ions and mercury ions were tested and analyzed.The data indicated that the PANI electrode showed excellent detection performance.The detection limit for copper ions was 85.6pmol · L^-1,and for mercury ions was 27.2pmol·L^-1.3.Copper ions,lead ions and mercury ions were tested and analyzed by square wave stripping voltammetry（SWV）using EDTA@PANI/MWCNTs modified electrodes.It can be observed through the test results that EDTA@PANI/MWCNTs showed good electrochemical performance in the detection of copper ions,lead ions and mercury ions,with the detection limit of copper ions at 55.4pmol·L^-1,lead ions at 22 pmol · L^-1 and mercury ions at 17.8 pmol · L ? 1.Moreover,the sensor electrode displays good anti-interference and stability.The sensor can detect three kinds of ions at the same time.Finally,the recovery rate test in the real water sample is also effective.The disposable electrode sensor prepared in this paper has the advantages of high price-performance ratio,inexpensive,the average produce time of a single electrode in large-scale preparation is quickly,real-time monitoring,high sensitivity,low detection limit and other advantages,and is suitable for mass production.This study provides research ideas and technical support for real-time water sample detection and future construction of portable sensor equipment.