The Electro-optical properties of ZnO Nanowires Modified with Au Nanoparticles and its Application in Biomedical Area

• Main Authors: Siou-YiLin, 林修毅
• Other Authors: Shoou-Jinn Chang
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/499yy5

博士 === 國立成功大學 === 微電子工程研究所 === 104 === In this study, ZnO nanowires (NWs) was synthesized using the vapor-phase deposition method and applied for blood alcohol content (BAC) sensors, field emission devices, and nonenzymatic glucose sensors. A ZnO nanowire gas sensor was used to detect ethanol gas vaporized from newborn calf serum (NBCS) droplets containing ethanol. It was found that the ratio of the response of newborn calf serum (NBCS) without ethanol to that with ethanol varied strongly with the vaporization temperature (Tvap). The highest ratio, around 7.69, was obtained at a Tvap value of 80 °C. The effect of relative humidity during the sensing of NBCS vapor can be neglected because of the huge responses ratio (17.36). The responses measured at 400 °C were around 4%, 53.5%, 51%, 31%, 26%, and 21% for NBCS droplets containing 0%, 10%, 5%, 1%, 0.5%, and 0.1% ethanol, respectively. Au nanoparticles are adsorbed onto the surface of vertical ZnO nanowires to fabricate a field emitter. The effective field enhancement factor (β) reaches 2.9 × 104. The nanoparticle size is below 10 nm and the diameter of ZnO nanowires is around 50 nm. Under ultraviolet light illumination, the nano-size emitter has a β value of 4.2 × 104, which is more than that of pure ZnO nanowires. ZnO nanowires (NWs) synthesized on an Au electrode substrate with and witout Au nanoparticle (NP) modification are applied for glucose detection. A significant enhancement of glucose sensitivity is obtained with Au NP modification. The Au NPs/ZnO NWs/Au electrode has peak currents gradually increasing from 41.2 to 155.5 μA, and the ZnO NWs/Au electrode has peak currents increasing from 23.6 to 82.2 μA with glucose concentration (5, 10, 15, 20, and 25 mM) in cyclic voltammograms. Moreover, chronoamperometry results indicate that the response current of the Au NPs/ZnO NWs/Au electrode reached 140 μA in 18 mM glucose in 0.1 M NaOH whereas that of the ZnO NWs/Au electrode was only around 74 μA in 31.5 mM glucose.