Preparation Of Copper-based Sulfides For Application In Enzyme-free Glucose Sensor

Glucose enzyme sensor by glucose enzyme catalytic oxidation of glucose,however due to the high cost,unstable glucose oxidase,complex fixed program repeatability is poor,many parameters,such as temperature,humidity and pH value,can affect the catalytic activity),and are working to develop widely the enzyme glucose oxidation catalytic sensor biomass to replace glucose oxidase sensors.These non-glucose oxidants have the advantages of moderate price,high efficiency and simple operation.The combination of copper oxide with other materials can result in glucose detection with low detection limit,fast response and high sensitivity,as the combination can significantly improve the conductivity or/and synergistic effect.Therefore,the development of cupric oxide hybrid material is an effective way to improve the detection performance.Therefore,this paper summarizes the copper-based enzyme-free glucose sensor,mainly divided into the following three parts:Part Ⅰ:Highly efficient non-enzymatic glucose sensor based on Cu_xS hollow nanospheresHollow nanospheres Cu_x S（Cu₂S,Cu₇S₄,Cu₂O）can be rapidly synthesized by changing the ratio of Cu₂O to Na₂S.hollow nanospheres Cu_xS were characterized by various means of the size,morphology,crystal properties,element composition and catalytic glucose oxidation susceptibility.Among them,Cu₇S₄ hollow-like nanospheres exhibited highest glucose sensitivity of 3728.7μAmM^-1cm^-2 as compared to the other Cu_xS hollow nanospheres.The Cu₇S₄ hollow nanospheres show a linear responses of glucose concentration ranging from 1.0μM to 2.0 mM,with a limit of detection（LOD）of 0.023μM（S/N=3）.The obtained results indicate that Cu₇S₄hollow nanospheres as a promising candidate for non-enzymatic glucose sensing.Part Ⅱ:Hollow core-shell structured Cu₂O@Cu_1.8S spheres as electrode for enzyme free glucose sensingA hollow core-shell structure Cu₂O@Cu_1.8S was synthesized by simple in situ growth method.Compared with Cu₂O nanospheres,Cu₂O@Cu_1.8S has better performance for catalytic oxidation of glucose without enzyme.The sensitivity of Cu2O nanoparticle electrode to detect glucose without enzyme was 3630μA mM^-1cm^-2,with A linear range of 0.001-1.0 mM and A detection limit of 0.0678μM（S/N=3）,and showed better selectivity for glucose oxidation.Cu₂O@Cu_1.8S exhibits more superior performance mainly because of its hollow core shell structure,the synergistic effect between Cu₂O and cu1.8s,and the larger specific surface area after the formation of hollow spheres,etc.,which makes it have higher catalytic activity for glucose oxidation.Part Ⅲ:Study on the performance of Cu_xS（Cu₂S/CuS）sulfide catalyst in glucose sensor without enzymeNumerous efforts have been made in the food industry,medical diagnostics and biosensors to rapidly develop simple and reliable methods for detecting glucose.In this study,hollow structure Cu₂S/CuS（Cu_xS）nanospheres were prepared by a simple and low-cost two-step method.The morphology and structure of Cu_xS were evaluated by sem,XRD and XPS.The electrocatalytic performance of Cu_xS on glucose sensing was determined by cyclic voltammetry and current analysis.Compared with the corresponding Cu₂O spheres,the electrochemical results show that the Cu_xS electrode has higher catalytic activity,higher sensitivity,faster response time,excellent selectivity and low detection limit for the glucose oxidation reaction.