Study On Enzyme-free Glucose Sensor Of Cerium Oxide Composite Based On Ce-MOFs

The accurate determination of glucose content in solution is of special significance for food safety,environmental hygiene and even the prevention and treatment of special diseases.Enzyme-based electrochemical sensor method is the most widely used in many glucose content measurement methods,but at present,glucose oxidase(GOx),a general active substance of this kind of sensor,has many shortcomings,such as poor stability,difficult fixation and so on.Therefore,the enzyme-dependent enzyme-free sensor,which allows glucose to oxidize directly on the electrode surface,has been paid more and more attention by researchers.In recent years,the research on enzyme-free sensors is generally focused on noble metal materials with high activity,but the cost of this kind of materials is high,and the defects such as poisoning and inactivation seriously hinder its development.In this case,the transition metal and its oxides with low cost and good stability have gradually become the focus of research.Metal-organic frame material(MOFs)is a kind of porous material with high specific surface area and adjustable pores,which is formed by coordination polymerization of metal ions with organic ligand,and Its derived oxides have gradually become one of the important active materials for enzyme-free glucose sensors because they can retain the advantages of MOFs structure and have good stability.However,the low electron transport efficiency of simple excessive metal oxides seriously affects its performance.Based on the cerium oxide derived from Ce-MOFs,which has excellent electron transport efficiency,the transition metal oxide with catalytic activity is combined in this paper,and the composite is applied to the study of enzyme-free glucose sensor.The main research results are as follows:1.dumbbell-like ZIF-67/Ce-BTC nanocomposites with shell-core structure and large surface area were prepared by extended growth method.the properties of the samples calcined at different temperatures were compared.finally,the calcined material(ZC-450)at 450°c was selected as the enzyme-free glucose sensor for continuous testing.the sensor had a high sensitivity(790.746?A·mm^-1·cm²)and a wide linear range(83.75?M-27.84?M)and a low detection limit(5.5?M)at low active metal content.Moreover,the electrode has good stability and anti-interference.In addition,the electrode was used to measure glucose content in juice,and obtained high accuracy and precision.2.On the basis of the above results,butterfly ZnCo₂O₄/CeO₂ nanocomposites were successfully prepared by internal expansion growth method and pyrolysis method.The material has shell core structure,large specific surface area and graded pore.The enzyme-free sensor prepared by electrode(ZnCo₂O₄/CeO₂/GCE)based on the material has very high sensitivity(2161.78A·mm^-1·cm^-2)and short response time(<1s).The detection limit is 0.05,m(s/n=3).It has excellent selectivity and stability,and can be used for the determination of glucose in juice.