Fabrication And Properties Of Glucose Biosensor Based On Metallic Oxide Nanostructured Materials

In this dissertation, ZnO nanowire arrays and CeO2 nanowire arrays were synthesized and modified. They were used as substrates for the construction of glucose biosensors based on cross-linking method. Pt nanoparticle decorated ZnO nanowire arrays, CeO2 nanowire arrays and carbon modified CeO2 nanowire arrays were fabricated, respectively. The performances of glucose biosensors based on aforementioned substrates were also investigated.Firstly, well aligned ZnO nanowire arrays were synthesized by electrochemical deposition method and deposition potential was optimized. Subsequently, Pt nanoparticles were decorated on the surface of ZnO nanowire arrays by hydrothermal method and the influence of hydrothermal temperature and hydrothermal time on the morphology and composition of Pt nanoparticles decorated ZnO nanowire arrays was studied. Mixture solution containing 5 v/v% GLA,4.8 w/v% BSA and 300 U/mL GOx was cast onto Pt nanoparticles decorated ZnO nanowire arrays to fabricate biosensors for glucose detection in combination with microfluidic analysis. The sensitivity of glucose biosensors based on Pt nanoparticles decorated ZnO nanowire arrays and microfluidic analysis achieved 10.80?A·mM-1·cm-2.Secondly, CeO2 nanowire arrays were synthesized by hydrothermal method on the surface of Ni foam. The influence of hydrothermal temperature and time on the morphology and phase of CeO2 nanowire arrays precursors was investigated. The GOx was immobilized onto the surface of CeO2 nanowire arrays to fabricate biosensors for glucose detection with chronoamperometric technique. Glucose biosensors with high sensitivity, low detection limit and wide linear range were achieved with optimization of working potential and GOx concentration. Especially, the sensitivity was as high as 325.95?A·mM-1·cm-2.Finally, Carbon was decorated on the surface of CeO2 nanowire arrays and they were used as the substrate for the fabrication of biosensors. Glucose oxidase was immobilized onto the surface of carbon modified CeO2 nanowire arrays to detect glucose concentration. The results showed that biosensor based on carbon modified CeO2 nanowire arrays demonstrated good performance under working potential of-0.6V, and sensitivity was 206.5?A·mM-1·cm-2. In comparison, CeO2 nanowire arrays only exhibited good performance towards glucose detection at positive potential, but the selectivity of the biosensor based on CeO2 nanowire arrays is bad. However, glucose biosensor based on carbon modified CeO2 nanowire arrays demonstrates excellent performance under negative potential, which also shows superb selectivity.