Preparation Of Nickel-cobalt-based Two-dimensional Composite Material And Its Application In Non-enzymatic Glucose Sensors

The rapid and sensitive detection of glucose has important research significance in the fields of medical diagnosis and food industry.The high cost,easy inactivation,and immobilization process of glucose oxidase limit the development of traditional enzyme-type sensors,so it is essential to develop low-cost,high-performance nonenzymatic glucose electrochemical sensors.The key to improving the performance of nonenzymatic glucose electrochemical sensors is to prepare new electrode materials with high activity and high conductivity.The catalytic performance of single nano-oxide materials based on nickel and cobalt is limited.In this paper,a new two-dimensional nano-material with ultra-thin thickness,high specific surface area,excellent conductivity and abundant active sites is introduced as a carrier.The composite material of the two materials is designed to improve the performance of the nonenzymatic glucose electrochemical sensor.This topic combines the preparation technology of two-dimensional nanocomposites with electrochemical technology,expands the application range of two-dimensional nanocomposites,and at the same time realizes efficient detection of glucose.The research content of this thesis mainly includes the following three aspects:(1)MoS₂@Co₃O₄ Nanocomposites were prepared by simple hydrothermal method with two-dimensional(2D)MoS₂ nanosheets as base substrates The morphology,structure and composition of the morphology were analyzed by scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The nonenzymatic glucose sensor was constructed with MoS₂@Co₃O₄ nanocomposites.The results of cyclic voltammetry showed that the MoS₂@Co₃O₄ nanocomposites showed enhanced electrocatalytic performance compared with Co₃O₄ nanoparticle-modified electrodes.The sensitivity of the sensor was calculated to be 151.3?Am M^-1cm^-2 with a detection range of 0.01 m M to 5.9m M and a minimum detection limit of 0.39?M.At the same time,the sensor has good selectivity,stability and repeatability,and has been successfully applied to the detection of actual serum samples.(2)Ni Co₂O₄@Ti₃C₂T_x composites were prepared on the basis of 2D layered Ti₃C₂T_x by one-pot hydrothermal method and calcination.The morphology,structure and composition were characterized by SEM,TEM,EDS,XPS and XRD.The nonenzymatic glucose sensor was constructed by Ni Co₂O₄@Ti₃C₂T_x nanocomposites.The results of cyclic voltammetry showed that Ni Co₂O₄@Ti₃C₂T_x nanocomposites showed enhanced electrocatalytic performance compared with Ni Co₂O₄.The sensitivity of the sensor was calculated to be 228.4?Am M^-1cm^-2 with a detection range of 0.005 m M to 23.45 m M and a minimum detection limit of 0.21?M.At the same time,the sensor also has good selectivity,stability and repeatability,and it shows good recovery and accuracy when testing actual serum samples.(3)Ni O/Co₃O₄/C nanocomposites were prepared by one-step calcination method using ultrathin 2D Ni Co-MOF nanosheets as template.The morphology,structure and composition were characterized by SEM,TEM,XPS and XRD.The nonenzymatic glucose sensor was constructed by 2D Ni O/Co₃O₄/C nanocomposites.The electrocatalytic performance of the sensor for glucose was investigated by cyclic voltammetry and alternating current impedance.The sensor has a sensitivity of 530.8?Am M^-1cm^-2 and a detection range of 0.005 m M to 15.30 m M with a minimum detection limit of 0.13?M.At the same time,the sensor also has good selectivity,reproducibility and storage stability,and it also shows good recovery and accuracy when testing actual serum samples.