Discrimination Of Metal Ions And Pesticides In Food Based On Sensor Array

Mimicking the mammalian smell and taste systems,sensor array take advantage of artificial cross-response receptors.Compared with highly specific lock-key patterns,sensing elements in the sensor array could have different effects on analytes.In recent years,with the development of chemical sensing technology,sensor arrays based on chemical sensing combined with chemometrics have been widely used in the field of analysis and detection.The ingredients in food are complex and diverse.Meanwhile,during the process of food production,transportation and storage,many physical and chemical changes may occur in food,resulting in changes in food quality.This change is difficult to detect with the traditional detecting method,but the sensor array can solve this problem.Sensor array plays an important role in the identification and differentiation of food species,origin and quality.This paper designed three kinds of sensor arrays,successfully differentiated different kinds of metal ions and pesticides.Furthermore,the sensor arrays have been applied in food analysis and detection.The main work is as follows:(1)Four kinds of polymer dots were synthesized by suspension drop method,and then a kind of fluorescent sensor array based on polymer dots was constructed.Polymer dots doped with methyl gallate,n-propyl gallate and dodecyl gallate(Pdots-MG,PdotsNPG,Pdots-DG)were used as four detection channels of fluorescent sensor array.When different kinds of metal ions interact with polymer dots,the fluorescence intensity of polymer dots will change to different degrees.Linear discriminant analysis is used to distinguish and identify different kinds of metal ions.Furthermore,the fluorescent sensor array was successfully applied to distinguish different brands of bottled water.(2)A colorimetric array sensor based on nanozyme was developed to distinguish different kinds of metal ions and teas.The colorimetric array sensor is composed of three nanozymes,named Cu-ATP,Cu-ADP and Cu-AMP.After the interaction between metal ions and the nanozymes,the catalytic activity of the nanozymes change to different degrees.Different kinds of teas have different metal ion residues due to the influence of the origin and environment.By using the linear discriminant analysis to make the composition diagram,different brands of teas are distributed in different areas,which can distinguish and identify different brands of teas.(3)A colorimetric array sensor based on multi-enzyme inhibition was constructed to detect and distinguish pesticide residues in food.Three enzymatic reactions,AChE,BuChE and ALP,acting as detection channels for colorimetric array sensors.Different kinds of pesticides reacted with the enzyme,so that the catalytic activity of the enzyme has different degree of inhibition.Linear discriminant analysis was used to identify and distinguish different kinds of pesticides.Moreover,the colorimetric array sensor can also realize the discrimination and recognition of several kinds of organophosphorus pesticides.