An Oxygen Sensor Based On Fluorescence Quenching

Optical oxygen sensor based on the fluorescence quenching was developed. We tried to establish a real time,rapid,accurate method to motor the concentration of dissolved oxygen in water. This dissertation consists of the following three chapters. The first chapter is the review of the literature. We summarize a variety of methods of measuring the concentration of dissolved oxygen, particularly emphasizing on the research and development of fiber-optical chemical sensors. Several polymers for optical oxygen sensors were discussed in this chapter. At last the signification,purpose,and the main content of the dissertation are put forward. The second chapter is about theories and methods. It is emphasized on the theory of dynamic fluorescence quenching and the basis principle of porous plastic optical fiber probe. The process how the probe is prepared is described in detail. In the third chapter, we studied the plastic porous probe which was made by tetrafluoropropyl methacrylate and isobutyl methacrylate as monomer, diethylene glycol dimethacrylate as cross-linking agent and the Ru(â…¡) complex as dye. The probe was prepared by a copolymerization technique. The effects of different polymer and material proportion on the sensitivity of the probe were investigated. The stability,reversibility,respond time of the probe were also studied. Under the condition of optiume compounding ration, the linear respond range of the probe was 0.3mg/L-10mg/L and the detection limit was 0.15mg/L. In the last chapter, we introduced the oxygen sensing film made by tetrafluoropropyl methacrylate. We selected tetrafluoropropyl methacrylate and isobutyl methacrylate as monomer, tributyl phosphate as plasticiser,Ru(â…¡) complex as indicator. The sensing film had a good sensitivity to dissolved oxygen. In the chapter we also discussed the respond time,stability,reversibility of the sensing film. The linear respond range of the probe was 0.3mg/L-15mg/L and the detection limit was 0.1mg/L.