Preparation And Biosensor Properties Of Iron - Based Compounds / Graphene Nanocomposites

Recently, electrochemical biosensor as the vital method for analysis and detection become the research hot spot. It is mainly to confirm the piece or the quantity of material via the electrochemical signal from the material and detective substance. In the field of biosensors, the electrochemical enzymeless sensor is the most widely used. Because it has so many advantages, such as high sensitivity, easy to stable, could be used in muddy solution, and so on. Moreover, the material in sensor electrode need not only serial better detective norm, such as lower limit detection, higher sensitivity and wider linear range, but also low price, high stability, recycle to use. This paper regards the graphene and the transition metal compounds as subject investigated, try to structure the compounds with transition metal nitrides and N-doped graphene, transition metal oxides/ reduced graphite oxide(rGO) with different morphology by shifting the ratios, temperature and surfactant. Finally, the compound with the best performance has been obtained. At the same time, we research the reaction mechanism on the glucose and H2O2 detection. The main research contents of this paper are as follows:(1) The negative Co or Fe nanosheets are secured on the position reduced graphite oxide via electrostatic interaction. Co2NX/NG and Fe2N/NG can be obtained through further nitridation. Because of the advantage of the two-dimensional especial structure, the synergistic effect makes the composites show high conductor, high catalytic activity and so on. Without the enzyme to detect the glucose, these composites exhibit high catalytic performance. This work not only proposes a new synthetic method on the nitrides assembly, but also expand the application of the nitrides on electrochemical biosensor.(2) Through the solvothermal, we anchor Co2+-DDA on the surface of graphite oxide using the electrostatic effect, based on long chain intertwined alkyl amine constructing the small particles assemble into the "spider" Co3O4 nanowires on reduced graphene oxide. After removing alkyl amine under high temperature, we synthetized the interconnected Co3O4 nanowires/rGO composites. The lauryl amine with long chain and the two-dimensional rGO effect on morphology. The design of multidimensional structure of the Co3O4 nanowires formed by Co3O4 particles and rGO composites not only has a large number of catalytic sites, but also improves the electronic directional transmission rate and promotes the diffusion of surface material to the active site. Because of the advantage of the performance, Co3O4 nanowires/rGO composites can be used to detect the H2O2 release of HepG2 cells in the drug stimulation in real time.(3) Through the solvothermal and further roasting, we synthetized the mixed phase Ni/NiO nanosheets using DDA assembly. Then we use the NiO/Ni ink to print on the graphene paper, which as the flexible electrode. Because of the existence of Ni, the NiO/Ni nanosheets obviously have higher conductivity and catalytic activity. The introduction of graphene paper as the flexible electrode to immoblize the catalytic agent has been greatly improves the NiO/Ni’s poor electrical conductivity, increases the active material and the material of the contact area and further improves the catalytic performance of the electrode.