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

  • 林 修毅

Student thesis: Doctoral Thesis

Abstract

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
Date of Award2016 Sep 8
Original languageEnglish
SupervisorShoou-Jinn Chang (Supervisor)

Cite this

The Electro-optical properties of ZnO Nanowires Modified with Au Nanoparticles and its Application in Biomedical Area
修毅, 林. (Author). 2016 Sep 8

Student thesis: Doctoral Thesis