Preparation Of Transition Metal-based Composite Nanomaterials And Its Application In Enzyme-free Glucose Sensor

Glucose is one of the basic nutrients to maintain mammalian life activities.The continuous high glucose concentration above normal level will lead to diabetes.It is one of the common chronic diseases,which seriously harms human health,so it is very important for quantitative detection of glucose concentration in human body.Most of the glucose detectors are based on enzyme,but enzyme sensors have many disadvantages,such as complex enzyme fixation process,expensive price and short shelf life,so more and more enzyme-free glucose sensors are developed and applied.In this study,three novel enzyme-free glucose sensors were prepared by using the high catalytic performance of transition metals and the high conductivity and specific surface area of carbon materials.Their test conditions were optimized to make the performance of the sensors more stable.Finally,they were successfully applied to the detection of glucose in real human serum samples.The specific research contents are as follows:（1）Co-MOF-74 was synthesized by simple solvothermal method,Co@C was derived from high temperature pyrolysis method,a novel enzyme-free glucose sensor was constructed by modifying Co@C on glassy carbon electrode（GCE）.Co@C materials with high catalytic performance can catalyze oxidation of glucose in alkaline medium,so as to realize the quantitative detection of glucose.Nafion/Co@C/GCE showed the lower detection limit of 4.76μM（S/N=3）for glucose detection,and the linear range was 200～4000μM,the sensitivity was 38.75μA·m M^-1·cm^-2.（2）The bifunctional catalytic system MnCo-MOF-74 was synthesized by solvothermal method and Co/Mn O@HC was obtained by high temperature pyrolysis.The enzyme-free glucose sensor was constructed on glassy carbon electrode.The introduction of Mn O not only improved the stability and sensitivity(233.8μA?m M^-1?cm^-2)of the sensor,but also widened the linear range of the modified electrode（50～900μM;1.9～6.9 m M）,and the detection limit was 1.31μM（S/N=3）.（3）In the process of synthesizing ZIF-67,NiO with high catalytic performance was added,and NiO/Co₃O₄@C two-dimensional heterojunction materials were obtained by pyrolysis NiO@ZIF-67 in air at the temperature of 500℃.The enzyme-free glucose sensor Nafion/NiO/Co₃O₄@C/GCE was constructed by modifying NiO/Co₃O₄@C on glassy carbon electrode.The linear range of the modified electrode was 5～4000μM,detection limit was 2.28μΜ（S/N=3）,and the recoveries were in the range of 98.9～99.7%in the real samples detection.