The Study On The Synthesis And Design Strategy Of Nickel-based Glucose Biosensing Materials

The core of biosensor is sensitive material,the selection and design of appropriate sensitive material is the key to obtain glucose biosensor with high-performance but low-cost.Nickel-based nanomaterials,such as metal nickel,nickel oxide,nickel hydroxide,have been widely used in non-enzymatic glucose biosensors and achieved satisfactory performance.However,in the numerous reported work,nickel-based sensitive-materials still existed the problems of inferior intrinsic catalytic activity and poor electron-transfer kinetic properties,which greatly limited the performance of the nickel-based biosensor to be further improved.In this thesis,to fabricate high-performance glucose biosensor for the detection of human serum,the general selection and design rules of sensitive-materials were explored by the regulation of intrinsic catalytic activity and electron-transfer kinetic toward the nickel-based nanomaterials based on the synthetic technique of hierarchical porous nanostructure.Based on the mesoporous KIT-6 material,a three-dimensional periodic mesoporous NiO sensitive-material was synthesized via a hard template method and applied to the study of glucose-sensitive properties.It was confirmed that the construction of hierarchical porous nanostructure is conducive to improve the performance of biosensor electrodes.The result lay the foundation for the optimization and design of high-performance glucose-sensitive materials.Spinel structured hierarchical porous NiCo2O4 hollow nanospheres were prepared by the "coordinating etching and precipitating" process.Through a series of material characterization and study of glucose-sensitive properties,the NiCo2O4 material turned out to be a high-performance glucose-sensitive material.Moreover,according to its unique synergistic catalytic effect and high conductivity characteristics,it was proposed that intrinsic catalytic activity and electron-transfer kinetic are the two key points for the selection and design of sensitive-materials.In the aspect of electron-transfer kinetic,a three-dimensional NiO hollow sphere/reduced graphene oxide composite was constructed by the introduction of the high conductivity graphene material.The effect of conductive substrate on the electron-transfer kinetic of NiO intrinsic material was investigated and the sensitivity of NiO to glucose was greatly enhanced.The biosensor with sensitivity up to 2.339 mA·mM-1·cm-2 was obtained through designing a three-dimensional NiCo2O4 hollow sphere/reduced graphene oxide composite,which further confirmed the correctness of the optimization strategy on electron-transfer kinetic.In the aspect of intrinsic catalytic activity,a Ni(OH)2/NiO composite nanosheet composite was synthesized via a microwave-assisted hydrothermal method.The effect of defect-engineering on the intrinsic catalytic activity of two-dimensional nanostructured sensitive-materials was discussed.Notably,the high performance glucose biosensor was also established.Based on the study above,it can be concluded that there existed some basic rules for the selection and design of glucose biosensor sensitive-materials.From the point of view of the intrinsic catalytic activity,the increase of the number of catalytic active sites and the acceleration of the catalytic frequency of the active site are the main purposes.The common means is to construct the synergistic catalytic system or carry out the defect-engineering and expose active crystal face of the sensitive-materials.From the point of view of electron-transfer kinetic,reducing the internal resistance and shortening the electron transport path of the materials are the fundamental purposes.The common effective ways are designing complex high-conductivity substrates and forming strong interface interactions.Additionally,the rules were applied to the construction of colorimetric glucose biosensors and photoelectrochemical glucose biosensors with satisfactory results.Moreover,the obtained NiCo2O4 hollow sphere/reduced graphene oxide composite material was also applied to the electrochemical detection of hydrogen peroxide,and a detection level of ?M could be achieved.