Surface Plasmon Resonance Technology Based Optical Fiber Chemical Sensor

Fiber-optic sensors based on surface plasmon resonance(SPR)not only have the features of fiber-optic sensors such as small volume,low energy consumption,rapid detection,anti-electromagnetic interference and real-time online detection,but also have the advantages of high sensitivity and label-free detection.The fiber-optic SPR sensor has become a hot research topic in the field of sensing and detection.In this thesis,sensing properties of fiber SPR sensors with chemical surface modification were studied theoretically and experimentally.The main research work are summarized as follows:(1)The structure of the fiber SPR sensor was improved by increasing the length of sensing area,such that the sensing area and mirror of the sensor can be assembled separately.The sensor was used to detect NaCl solutions with different concentrations.As the refractive index increases,the resonant wavelength of the SPR sensor shifts to longer wavelengths.Besides,the sensitivity gradually increases with the resonant wavelength.And also,temperature effect of the sensor was studied.(2)An optical fiber SPR sensor with surface-grown zinc oxide(ZnO)nanorods was prepared by hydrothermal growth method.The effect of pulling times of the probe in the seed solution on the root film layer of the zinc oxide nanorods were analyzed.Growing situations of ZnO nanorods with different growth time were studied.(3)By changing the probe's pulling times and growth time in the seed solution,the effects of ZnO nanorods with different growth conditions on the performance of the fiber SPR sensor were studied.It is found that the root layer of ZnO nanorods has the greatest impact on the sensor's performance.When synthesized in the same growing environment,the more the number of pulling,the longer the growth time of the same pulling times,the denser the root membrane and the greater the thickness As density and the thickness of the root layer of ZnO nanorods increases,the linewidth of the SPR resonance become larger.Increasing the thickness and density of the rootlayer within a suitable range can shift the SPR resonance to longer wavelength and increase the sensitivity of the sensor.(4)A glucose sensor was developed based the ZnO nanorods-on-fiber SPR sensor which was surface modified by glucose oxidase.The fabrication process was optimized to improve the performance of the sensor.The sensor has good selectivity to glucose.The sensor has a sensitivity of 1.761 nm/mM within the detection range of0-10 mM.