Patterned growth of ZnO nanorods and enzyme immobilization toward the fabrication of glucose sensors

Toward the fabrication of high sensitive glucose sensors based on ZnO nanorods integrated with ZnO-based FETs, patterned growth of ZnO nanorods and enzyme immobilization on their surfaces were conducted. The patterned growth of ZnO nanorods using photoresist was successfully performed on both sputtered polycrystalline ZnO films and epitaxial singlecrystalline ZnO ones using a hydrothermal method, although choice of a proper condition is required for the latter case. Glucose oxidase (GOx), a specific enzyme for glucose detection, was immobilized with both covalent and electrostatic bonding methods. GOx immobilized ZnO nanorods were characterized with X-ray photoelectron spectroscopy, scanning electron microscopy, and colorimetric measurements indicating that the GOx was effectively immobilized on the large surface area of ZnO nanorods.