Preparation Of Composite Nanoparticles And Its Application In Biosensor

Electrochemical Biosensor will be widely used in clinical medicine and modern life science because of its high sensitivity, wide linear range and easy to operate. Glucose Electrochemical Sensor and Electrochemical Immunosensor performed well in early diagnosis and treatment of illness, which drew much attention from the vast number of sensor researchers. Functions of Electrochemical sensor mainly depend on the carrier materials, so designing and synthesizing carrier materials with good biocompatibility becomes the key to Electrochemical Sensor research. This thesis mainly starts with the synthesis of interface materials, dedicates to produce carrier materials with high activity and good biocompatibility, and then apply them to the construction of Electrochemical Sensors. The writer expects to gain Glucose Electrochemical Sensor and Electrochemical Immunosensor with good stability, high sensitivity and easy to be miniaturized.In the first chapter, it introduces the functions of nanomaterial and its using in Biosensor. And it also elaborates specifically the concept, classification and working principles of Biosensor.In the second chapter, the writer produces Ferroferric Oxide Nanoparticles(Fe3O4 NPs) which with superparamagnetism by oxide co precipitation. And then gets Fe3O4/PEI composite nanoparticles by combining with Polyethylene Imine(PEI). The writer forms carrier materials Fe3O4/PEI/Au with Ferroferric Oxide(Fe3O4)as the nucleus, PEI as the shell and Au adsorbed on the surface by combining with Nanogold(Au) through electrostatic adsorption. And finally constructed the Sensor with Fe3O4/ PEI/Au as the carrier by combining with Glucose Oxidize(GOx). The writer use SEM, Ultraviolet-Visible(UV)and other instruments to represent the morphology, structure and property of the basal material; Use comprehensive electrochemical analyzer to explore the property of the Sensor. TG shows the amount of PEI covering on the surface of Fe3O4 NPs is 23.31%. The response time is 0.5 s, and the sensitivity is 60. 87 μA mM-1cm-2 and the linear range is 0~10 mM.In the third chapter, the writer produces carrier materials with good biocompatibility by using magnetic Nanoparticles, Polyethylene Imine(PEI) and Nanogold as the base, and applied them to Glucose Sensors. The writer obtains PEI/Fc compounds by the reaction between the-NH2 in the molecular structure of Polyethylene Imine(PEI) and-COOH in ferrocene and its derivatives(Fc) according to the principle of Schiff base reaction. And then gets the modified materials with Fe3O/PEI/Fc/Au compounds as the carrier by combining them with Ferroferric Oxide Nanoparticles(Fe3O4 NPs) and Nanogold(Au), and finally gets Glucose Sensor constructed by Fe3O4/PEI/Fc/Au/GOx composite nanoparticles by combining with GOx. The writer use SEM, ultraviolet-visible(UV) and other instruments to represent the morphology, structure and property of the basal material; Use comprehensive electrochemical analyzer to explore the property of the Sensor. It shows the covering amount of PEI/Fc on the surface of Fe3O4 NPs is 7.22%, the response time is 0.3 s, and the sensitivity is 62.71 μA mM-1cm-2 and the linear range is 0.09 mM.In the fourth chapter, with magnetic nanoparticles as basical materials, the writer gets Fe3O4/PEI/Fc magnetic nanoparticles compounds through electrostatic adsorption with the PEI/Fc compounds, and gets basal materials with good biocompatibility by adsorbing Nanogold. Finally, the writer constructs good Immune Sensor by immobilizing them on antigen and antibody. The writer use SEM, ultraviolet-visible(UV) and other instruments to represent the morphology, structure and property of the basal material; Use comprehensive electrochemical analyzer to explore the property of the Sensor. It shows the response time of Sensor is 0.9 s, and the test line is 0.89 ng/mL.