Self-supported Ni-MOF Derived Materials As Non-enzymatic Glucose Sensors

Diabetes mellitus has become one of the diseases threatening the health of global human due to its damage to the multiple systems in human body.To reduce the incidence of diabetic complications resulting from persistent hyperglycemia,the long-term regular test of blood glucose concentration is essential for people with diabetes in their daily life.Therefore,development of efficient and reliable glucose sensors is of paramount importance.Currently,commercial blood glucose meter is based on the enzymatic glucose sensors,in which the active material on its test paper is glucose oxidase.Enzyme as the high-cost bioactive molecule and the complicated enzyme-immobilization process can result in the high-cost of the enzymatic glucose sensors.Therefore,many attempts have been made to construct low-cost and stable non-enzymatic glucose sensors based on various metals and carbon-based materials so as to replace the enzymatic glucose sensors.In recent years,some researches aim to prepare metal-organic frameworks(MOFs)derived materials with excellent electrocatalytic activity toward the oxidation of glucose,in which metal-organic frameworks serve as sacrificial templates or precursors.However,most MOFs derived materials are of powder states.Furthermore,the fabrication strategy of working electrodes is using adhesive to immobilize them onto conventional electrodes,which can result in complicated preparation,easy peeling off of the electroactive materials and poor stability.On account of this,nickel foam was employed as the substrate to in-situ grow Ni-MOF by hydrothermal synthesis method in this paper.And then,the self-supported Ni@C nanoshees electrode and CuNi@C electrode were fabricated using Ni-MOF on nickel foam as precursor template.The electrodes were used to construct non-enzymatic glucose sensors,and the performance of the sensors was studied.The main research results were expressed as follows:(1)The self-supported Ni@C nanosheets electrode was manufactured by hydrothermal synthesis with successive pyrolysis.The electrode was provided with three-dimensional hierarchical porous structure and exhibited remarkable electrocatalytic activity toward the non-enzymatic monitoring of glucose.The results showed that the sensitivity of the electrode was as high as 32.7944 mA·mM-1·cm-2,which was much higher than some nickel-based materials.The linear range from 0.15 ?mol·L-1 to 1.475 mmol·L-1 and the low detection limit of 50 nmol·L-1 were obtained.The electrode showed excellent selectivity toward glucose,acceptable reproducibility,satisfying long-term stability and high tolerance to chloride ions.The self-supported Ni@C nanosheets electrode demonstrated the practicability in detecting human blood serum samples with appealing accuracy and precision.(2)The self-supported CuNi@C electrode was prepared by the constant-potential electrodeposition based on the self-supported Ni@C nanosheets electrode.Cu nanoparticles were grown on the surface of the electrode uniformly.The electrode showed excellent property on non-enzymatic glucose sensing due to the synergistic catalysis between Cu and Ni.A sensitivity of 17.1203 mA·mM-1·cm-2,the linear range of 0.2 ?mol·L-1 to 2.7206 mmol·L-1 and the detection limit of 66.67 nmol·L-1 were achieved in this research.The electrode possesses not only excellent specificity to glucose,but also the attractive reproducibility,long-term stability and high tolerance to chloride ions.The similar results with the hospital test report were obtained in the detection of human blood serum samples,implying the application value of the electrode.