Abstract:Enzyme is susceptible to environmental conditions and the catalytic activity of enzyme is easily denatured. Due to the poor stability and reproducibility of the enzymatic sensor, its application is limited. The development of the nonenzymatic glucose sensors provide a promising new way for glucose detection in blood, which avoid the drawbacks of the enzymatic sensors and the direct electrocatalytic oxidation of glucose at surface of the modified electrode. This paper consists three works as follows:The first fraction of this thesis focused on the synthesis of ZnO nanostructures by potentiostatic electrodeposition. Four morphologys of nano-ZnO such as fusiform, rod, tube, hexagonal prism shape were prepared. The nanorod ZnO can be obtained when the applied potential is-1.0V and the growth temperature is80℃with a period of30minutes. According to the data table of particle size distribution, nanorod was mainly110-140nm in average diameter, which decreased150nm than hexagonal prism ZnO. The XRD profiles showed that the prepared ZnO were attributed to wurtzite hexagonal nanostructures. Finally, the for-mation mechanism of different nano-ZnO was also discussed.The second fraction of this thesis was to decorate Cu nanoparticles on ZnO for the fabrication of nonenzymatic glucose sensor. This sensor based on Cu-NPs/ZnO nanorod arrays modified FTO conductive glass was constructed by electrodeposition. The results of SEM、XRD、EDS clearly suggested that Cu nanoparticles were attached onto the surface of ZnO nanorod successfully. The CV and EIS electrochemical tests indi-cated the modified electrode possessed larger surface area and higher electrocatalysis activity toward glucose.+0.7V was selected as the optimal potential for glucose detection and5min for Cu deposition. Under the optimal conditions, the modified electrode offered a rapid response to glucose in the range from5×10-6M to1.1×10-3M (R=0.9975) with a detection limit of3×10-7M (S/N=3) and a sensitivity of609.8μA·mM-1.The Cu-NPs/ZnO nanorod arrays glucose biosensor showed6.1%response current compared to glucose in the presence of ascorbic acid and there is no significant effect on the current response towards uric acid, indicating high specificity and stability to glucose.In chapter4, a new enzyme-free glucose sensor was developed using continuous cyclic voltammetry to oxidize Cu nanoparticles. XRD showed that CuO was completely formed during CV and the mechanism of the CuO electrodeposition was shown in the paper. The effects of different scan rates on the oxidation of1mM glucose illustrates that the elec-trochemical kinetics are controlled by surface adsorption of glucose mol-ecules. The optimal electrodeposition potential for Cu was determined to be-0.4V and the NaOH concentration is0.1M. From the ladder graph,+0.55V was selected as the optimal constant detecting potential. The upper glucose concentration limit for linear response was2.0mM and the detection limit was5×10-7M (at signal/noise=3) with a sensitivity of1673μA·mM-1. The CuO/ZnO nanorod arrays glucose sensor possesses excellent performance owing to its high sensitivity, good stability, repro-ducibility and interference-free of co-existed substances. Therefore, the CuO/ZnO nonenzymatic glucose sensor had a promising application for glucose determination. |