Basic Research On The Application Of Immobilized Enzyme In Fiber Optic Biosensing Technology

The determination of numerous biological parameters in human body is extremely important to the prevention,diagnosis and treatment of various disease.Glucose and cholesterol are two most common biomass in the human body.It's of great clinical significance for the diagnosis and treatment of diabeticpatients to detect blood glucose,and the detection of cholesterol concentration is helpful for the prevention and treatment of cardiovascular and cerebrovascular diseases.With the development of science and technology,the requirement to the detection of biological parameters becomes more and more complex,resulting in a variety of scientific detection technology.Among these detection methods,fiber optic biosensor technology plays a significant role in the fields of chemistry,environment,biology,biochemistry and medicine,and others.In this thesis,several fiber optic glucose sensors and fiber optic cholesterol sensor have been designed and fabricated based on the combination of immobilized enzyme,intelligent hydrogel,and optics system,and their properties have been studied,which lay a foundation for the investigation of multiple parameters fiber optic biosensors.In this thesis,the main completed research works are in the following:?1?Porous fluorescent SiO₂ nanoparticles were prepared and characterized,and the optimal conditions for the immobilization of COD on porous fluorescent SiO₂nanoparticles were investigated.The thermal stability,storage stability and operation stability of the immobilized COD were studied.Based on porous fluorescent SiO₂ nanoparticles immobilized COD,a fiberoptic cholesterol sensorwas fabricated.Theproperties of this sensor were studied and the optimal detection conditions were obtained.The phase delay of this sensor has good linear relationship with cholesterol concentration in the range of 0-100 mg/dL,having the standard curve equation of y=0.02600+0.002420x and R²=0.9948.The repeatability and ability of resisting disturbance of the sensor were studied,and the determination of the practical samples were performed.?2?The hydrogel--immobilized GOD complex were prepared and characterized,and their properties were studied.The influences factors to the properties of hydrogel-immobilized GOD complex were studied and its“on-off”effect on the catalysis to glucose oxidation was investigated.A fiber optic glucose sensor based on hydrogel-immobilized GOD complex was designed and fabricated,and the influence of detection conditions on the sensor properties were studied.The temperature controlling detection of glucose was performed by this sensor.The phase delay of this sensor has good linear relationship with glucose concentration in the range of 50-600 mg/dL,having the standard curve equation of y=0.02152+0.0005229x and R²=0.9871.The repeatability and ability of resisting disturbance of the sensor were studied,and the determination of the practical samples were performed.?3?An optical platform was set up and a fiberoptic glucose sensor using Ru?bpy?₃Cl₂ and lucigenin as indicators was fabricated.The multimode fiber was used as the sensor head.Using this sensor,glucose concentrations were detected and sequence diagram and standard curve were obtained.The anti-interference ability of sensor was investigated.