Study On The Application Of Electrospun Micro/Nanoifbers Modiifed Electrode In Electrochemical Sensors

Due to their high surface-to-volume ratio and high aspect ratio, one dimensional （1D）micro/nanomaterials have been widely applied in many fields, especially in the field ofchemically modified electrode because1D micro/nanomaterials can significantly increaseelectrode surface area and help the electron transfer. Therefore, the preparations of1Dmicro/nanomaterials modified electrode using various techniques have attracted great interest.Electrospinning technique is an efficient method for preparing1D micro/nanofibers modifiedelectrode. In this thesis, transition metal oxides microfibers modified electrodes fornonenzymatic glucose sensors and polyoxometalate （POM） hybrid nanofibers modifiedelectrode for nitrite sensor fabricated by electrospinning technique were investigated. Themain achievements are summarized as follows:1. Fluorine tin oxide （FTO） electrode modified by CuO microfibers composed ofnumerous interconnected CuO nanoparticles for nonenzymatic glucose sensor was preparedby electrospinning precursor containing high percentage content of copper nitrate withsubsequent calcination. The results of scanning electron microscope （SEM） showed the sizeof CuO particles composing CuO microfibers depended on the percentage content of coppernitrate in precursor solution. With increasing the percentage content of copper nitrate, theinterconnected CuO nanoparticles would gradually replace the large-size CuO particles toaccumulate the CuO microfibers, which have the potential to provide larger surface area andmore reaction sites for electrocatalytic performance toward glucose.2. NiO microfibers were directly immobilized onto the surface of FTO electrode byelectrospinning and calcination for nonenzymatic glucose sensor. The results of cyclicvoltammetry and amperometry proved that calcination temperature has an influence on theelectrocatalytic performance toward the oxidation of glucose at the NiO microfibers modifiedelectrode. The electrocatalytic performance of the NiO microfibers modified electrodedecrease gradually with increasing the calcination temperature. The NiO microfibers modifiedelectrode prepared at low calcination temperature （300℃） presented remarkableelectrocatalytic performance toward the oxidation of glucose. This is because the decrease ofthe conductivity of NiO with the increase of calcination temperature.3. An improved nonenzymatic glucose sensor based on CuO-doped NiO compositemicrofibers modified FTO electrode was prepared by electrospinning and calcinationtechnique. The results of cyclic voltammetry and amperometry demonstrated that theCuO-doped NiO composite microfibers modified electrode displayed much higherelectrocatalytic performance than the NiO microfibers modified electrode, which can be mainly attributed to the resulting increase in conductive and reaction sites at NiO microfibersinduced by doping CuO. Additionally, its application for detecting glucose concentration ofhuman serum sample showed good agreement with the results obtained from automaticbiochemical analyzer.4. POM hybrid nanofibers modified electrode was prepared by electrospinning of amixture of poly （vinyl alcohol）（PVA） and α-K₆[P₂W₁₈O₆₂]14H₂O (P₂W₁₈) onto surface ofindium tin oxide （ITO） electrode. After thermal crosslinking, the P₂W₁₈hybrid nanofibers areinsoluble in aqueous solutions, which ensure that the P2W18hybrid nanofibers modifiedelectrode could be applied as nitrite sensor. The results of cyclic voltammetry andamperometry demonstrated that the P2W18hybrid nanofibers modified ITO electrode exhibitsexcellent electrocatalytic performance toward the reduction of nitrite. Additionally, long-termstability and reproducibility were observed.