Study On Enzyme-free Glucose Sensor Based On Co₃O₄ Transition Metal Oxide Electrode

The glucose sensor based on electrochemical principle has the advantages of high sensitivity and easy operation,and can quickly detect human blood glucose concentration.It has been widely used in the medical field and has far-reaching significance for the diagnosis and prevention of diabetes.At present,the glucose sensor used on a large scale in the market uses glucose oxidase as an active material.Due to the inherent high manufacturing cost,harsh test environment and poor stability of the biological enzyme,it faces the current increasing market demand.It seems to be stretched.The enzyme-free glucose sensor developed by using transition metal oxide has the characteristics of low cost,high stability and high sensitivity,and has received more and more attention.Based on Co₃O₄,the effects of composition and morphology of transition metal oxides on the detection performance of glucose were studied by improving the morphology and composition of transition metal oxides.Based on Co₃O₄,a Co₃O₄/Ni composite electrode was synthesized on a foamed nickel substrate by hydrothermal method.The experimental results show that the synthesized Co₃O₄material has a unique multi-level flower cluster structure with a specific surface area of 17.886m²·g^-1.In an alkaline environment,the Co₃O₄/Ni composite electrode exhibits good glucose detection performance with a detection limit of 1.17?M,a linear range of 0 to 5 mM,and a sensitivity of 7.4 mA·mM^-1·cm^-2,and has a good anti-interference performance.From the perspective of improving the surface morphology,on the basis of hydrothermal synthesis of Co₃O₄/Ni composite electrode,a precursor with a hydrothermal synthesis process was modified by alkali treatment to obtain a Co₃O₄ with high specific surface area.The test results show that the BET specific surface area of the high specific surface area Co₃O₄/Ni material is increased to 29.733 m²·g^-1,and the structure of the material is more fluffy and porous.The electrochemical detection of glucose showed that the sensitivity of the prepared high specific surface area Co₃O₄/Ni composite was significantly improved,reaching 13.855mA·mM^-1·cm^-2,the detection limit was 1?M,and the linear interval was about 0³.6 mM,anti-interference performance is also reliable.From the perspective of improving the composition of the material,the CuCo₂O₄/Ni composite electrode was synthesized by hydrothermal method on the basis of hydrothermal synthesis of Co₃O₄/Ni composite electrode.The morphological characterization results show that the CuCo₂O₄ material on the surface of the electrode is aggregated through a large number of nano-needle structures with a diameter of about 40 nm to form a layer of frame structure film.The specific surface area of this structure reaches 22.244 m²·g^-1.The electrochemical test results show that the CuCo₂O₄ material has stronger electron transfer ability and the electron mobility is as high as 1.83 s^-1.Combined with this high specific surface area nanostructure,the detection sensitivity of CuCo₂O₄/Ni composite electrode for glucose is significantly improved,reaching 15.950 mA?mM^-1?cm^-2.The detection linear range is 0².4 mM,and the detection limit is 1.36?M,while maintaining good anti-interference.