| Summary: | 碩士 === 國立臺南大學 === 電機工程學系碩博士班 === 104 === The chemical solution processes had been used to grow the nano structures of ZnO. Firstly the dipping method was used to grow the ZnO seed layers with platinum nano particles on ITO glass substrates.Then the ZnO nano structures were grown by hydrothermal method and finally assembled as cholesterol biosensors.
Diluting the concentrations of Znic acetate and Sodium hydroxide during the dipping process resulted in thinner seed layers of ZnO which led to a higher density of ZnO nanostructures in the hydrothermal growth process and a higher sensivity of cholesterol biosensors can be obtained.
The main study purpose of this study is to conclude the thickness of the ZnO seed layer and the amount of platinum nano particle effects on the sensing performance of ZnO cholesterol biosensors. The material properties of ZnO seed layer and nano structures were analyzed by SEM、XRD and AFM.The biosensor properties were detected by Cyclic Voltammetry.
When the pulling speed of the ITO glass substrate was 60mm/min,the final ZnO cholesterol biosensor had the highest sensitivity of 3.37 µA (mg/dl) -1 cm-2 (130.39µAmM-1 cm-2 ),Km value of 4.84mM and response time of 5 seconds in the liner detectable range between 0 to 500mg/dl. Although importation the platinum nano particles on the surface of ZnO seed layers will decrease the absorption amount of ChOX,but effectively increased the catalyst effect and led to high sensitivity and less response time.
The results had shown that increasing the surface area, the density of ZnO nano structures,the thicknessed of ZnO seed layer and the absorption amount of platinum nano particles had directly effects on the performance of the ZnO cholesterol biosensors.
Key words:
sol-gel,dipping,hydrothermal process,ZnO seed layer,ZnO nanostructures,
cholesterol biosensors
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