Research On Preparation And Application Of Composite Polyaniline Electrochemical Sensor

Urea and creatinine are the most common indices for the evaluation of kidney features by routine biochemical tests.It is of great importance to construct flexible,portable,real-time monitoring,and low-cost disposable electrochemical sensors to detect them.This paper proposes a method for preparing a disposable full-printed electrochemical sensor based on multi-walled carbon nanotubes(MWCNTs)/polyaniline(PANi)composite material,and uses it for the rapid detection of urea and creatinine.For electrochemical sensors,electrode modified materials are the most important part,and the selection of appropriate materials can significantly improve the performance of electrochemical sensors.MWCNTs form a good conductive channel inside PANi,which can make up for the insufficient conductivity of polyaniline,and the electrochemical capability of the electrochemical sensor was significantly enhanced.Therefore,this article first doped polyaniline with three different qualities of MWCNTs to prepare different MWCNTs/PANi electrodes,and compared the detection effects of these three electrodes and pure PANi electrodes on urea,and found that 5.6mg MWCNTs doped Polyaniline material has the best electrochemical performance.Second,according to the principle that PANi has a good detection effect on metal ions,and the principle that metal ions and creatinine can form a creatinine-metal complex,Cu(II)is used as an intermediate substance,and a mixed solution of Na₂SO₄and Cu Cl₂was used as a buffer.The PANi electrochemical sensor for measuring creatinine content was prepared.The sensor has many advantages that traditional sensors do not have:simple operation,convenient equipment and simple reaction environment.By adjusting the concentration ratio of Na₂SO₄and Cu Cl₂in the buffer,the electrochemical performance of the sensor for detecting creatinine was improved.Finally,based on the least squares method,an algorithm was devised to optimize the data to find the best response voltage of the electrochemical sensor,avoiding some errors caused by artificial estimation of the selected voltage,and it was applied to the data analysis of urea and creatinine.Experiments show that compared with manual estimation,the optimization method in this paper can quickly approach the target and find the optimal working voltage.Through algorithm optimization of the selected voltage,the detection limit,sensitivity and linear range of the MWCNTs/PANi electrochemical sensor for urea were 53.9 n M,2.435×10^-4m A m M^-1cm^-2and 10 to100?M,respectively.Compared with manual estimation,the performance of MWCNTs/PANi electrochemical sensor was greatly enhanced.The detection limit,sensitivity and linear range of the prepared MWCNTs/PANi electrochemical sensor for creatinine were 1.494 n M,87.9×10^-4m A m M^-1cm^-2?0.1 to 100?M,respectively.