Development of a Novel SPR-based Gas Sensor with ZnO Nano-structure

• Main Authors: Wei-Yi Feng, 馮偉意
• Other Authors: Chii-Wann Lin
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/99850837400996003000

碩士 === 國立臺灣大學 === 醫學工程學研究所 === 96 === Surface plasmon resonance (SPR) sensing technique, which provides advantages of high sensitivity, non-contact, real-time, and parallel detection, has been developed and played an important role for biomolecular and biochemical sensor. In this study, we proposed to design SPR sensing chip combined with the Zinc Oxide (ZnO) nano-film as a novel optical SPR gas sensor. Depending on the optimal design of ZnO sensing film, it provided better SPR curve and sensitivity and in the future will be able to apply to nitric oxide (NO) detector, which is a critical index in asthma diagnostic, and environmental toxic gas sensor. In this study, we used the radio-frequency sputtering deposition system to prepare the ZnO nano-film. Because the sensing performance of ZnO is intimately related to the physical properties, for instance, the surface roughness, grain size, conductivity, photoluminescence…etc, the study of the electricity and optics as well as morphology are very important and could be the evaluation index for gas sensing performance. The physical characteristics of ZnO thin films were obtained by the analyses of XRD, SEM, and AFM. The optical properties of ZnO thin films with different sputtering parameters were also studied by measuring the photoluminescence spectrometer. In the experiments of this thesis, we have successfully combined the ZnO nano-structure with the SPR sensor to serve as a nitric oxide gas detector. According to the experimental result, it is found that under less oxygen sputtering environment, there is higher extent of oxygen vacancies in the ZnO thin film and, therefore, it has higher conductivity and stronger defect emission at the PL experiment. By combining the oxygen defect ZnO film with SPR, this novel type gas sensor provides several advantages such as fast, reversible, low working temperature and high sensitivity and is able to serve as a low-power required optical surface plasmon resonance gas sensor.