Preparation Of Copper Based Glucose Sensor And Modification Of Graphene

With the rapid increase of the prevalence of diabetes in the world,the demand for blood glucose detection is expanding.Therefore,the research on the performance improvement of self-test equipment is also deepening.As the most important part of blood glucose detection equipment,glucose sensor has become the main research object to improve the performance of the equipment.Based on the excellent performance of copper based materials in the catalytic oxidation of glucose and the important role of graphene,boron nitride and their heterojunctions in the electrochemical modification of metal based materials,this paper prepared copper based glucose sensor composites by thermal oxidation,graphene modification,boron nitride modification and heterojunction modification of copper based materials,and carried out material characterization and performance test.The main achievements are as follows:(1)Copper oxide layer was prepared on the surface of copper foil by thermal oxidation,and graphene was used to modify the composite of copper and its oxide.Taking the defects contained in graphene as the active sites by electrochemical stripping,the sample has a larger active surface area.The multiple oxidation system composed of copper and its oxides can promote the redox reaction between electrode materials and glucose.In addition,graphene uses copper oxide as the intermediate layer to avoid the strong interaction caused by the direct contact between copper and graphene,so as to further improve the electron transfer speed,Finally,the sensing performance of electrode materials is improved.The prepared copper/copper oxide/graphene composite has a sensitivity of 3102 μA mM-1 cm-2 and a detection limit of 1.35 μM in the linear range of 0.002-2.88 mM.(2)Graphene,boron nitride and graphene/boron nitride heterojunction were modified on the surface of copper foil by electrochemical stripping,and their properties were studied by changing the content of heterojunction.The results show that the surface of the composite material is formed with pore structure after heterojunction modification,that is,with the increase of the content of graphene/boron nitride heterojunction,the electrochemical surface area of the electrode material increases,and the graphene/boron nitride heterojunction affects the electron mobility of the electrode material,resulting in the increase of response current,and finally improves the sensing performance of the electrode material.The prepared copper/graphene/boron nitride composite has a sensitivity of 4503.06 μA mM-1cm-2 and a detection limit of 1.26 μM in the linear range of 0.002-1.38 mM.(3)The composite material is prepared by electroplating with graphite foil and graphene as the substrate to improve the conductivity and flexibility of the electrode material with copper foil as the substrate.The results show that graphene/boron nitride/copper/graphene composite samples prepared with graphene as substrate have larger electrochemical active surface area,higher electron transfer rate and better adsorption,so it shows excellent glucose sensing performance.The sensitivity of graphene/boron nitride/copper/graphene composite is 4910.34 μA mM-1cm-2 in the linear range of 0.0015-1.88 mM,and the detection limit is 7.05 μM.