Research On Glucose Concentration Measuring Method Based On Fiber-optic Surface Plasmon Resonace Technique

Continuous detection of human glucose concentration can provide dynamicchanges during24hours. Minimally invasive glucose concentration detection is oneof continuous glucose concentration detection technologies in interstitial fluid (ISF)with a painless, easy-to-realize and short time measurement. It can be divided intotwo major categories: ISF transdermal extraction and implanted measurement. TheISF transdermal extraction detection requires a very high sensitivity of the sensor, dueto the small amount of the extracted ISF and the following dilution. For the implanteddetection, bioelectrical interference will bring a great influence to the measurementaccuracy. Therefore, minimally invasive glucose concentration detection has a veryhigh requirement on the sensor.In this thesis, a new glucose concentration measurement method based on thefiber-optic surface plasmon resonace technique is proposed, which can satisfy theclinical needs of minimally invasive glucose concentration detection. The accuracy ofthe measurement results is improved by side polishing to change fiber-optic SPRstructure, temperature compensation with fiber grating, boric acid polymerlayer-by-layer self-assembly surface modification technology and goldnanoparticles surface modification.Major work of this thesis can be included in five parts as follows:1. Theoretical analysis and structure parameters design of fiber-optic surfaceplasmon resonance sensorSurface plasmon resonance sensing theory is studied. Theoretical calculation model ofthe multimode online transmission fiber-optic SPR sensor, singlemode onlinetransmission fiber grating SPR sensor and multimode side-polished fiber optic SPRsensor are built. Simulation and parameters optimization of the online transmissionfiber optic SPR sensor and the multimode side-polished fiber optic SPR arecompleted.2. Temperature compensation method of the fiber optic SPR sensor based onlong-period fiber gratingIntegration of long period fiber grating and optical fiber SPR sensor is proposed basedon the mode coupling theory. Temperature characteristics of long period fiber gratingare studied and changes of the core and cladding are analyzed when the temperaturechanges. Optimal parameters and mode that is highly sensitive to temperature and not sensitive to refractive index(in the range of ISF refractive index) are determinedthrough simulation and calculation with Optiwave and Matlab.3. Manufacturing process of fiber-optic SPR sensorManufacturing process of the proposed SPR sensors are studied. Methods of vacuumcontrol, membrane material heating source and film thickness monitoring method arestudied. The fixture device of fiber is also designed and the coating of the optical fiberis completed by physical vapor deposition methods. Two-beam interferometer methodis utilized for the long-period fiber grating processing.4. Method of fiber-optic SPR sensor surface boric acid polymer modification bylayer-by-layer self-assemblyWater-soluble boric acid polymers PAA-ran-PAAPBA which can absorb glucosemolecule is used to eliminate interference from other ingredients. Then synthesis andpreparation of PAA-ran-PAAPBA are completed. The PAA-ran-PAAPBA is fixed onthe SPR sensor surface with layer-by-layer self-assembly surface modificationtechnology and then characterized with the quartz crystal microbalance.5. Glucose measurement experiments of fiber-optic SPR sensorGlucose measuring system with multimode online transmission fiber-optic SPRsensor, side-polished fiber-optic SPR, singlemode online transmission fiber gratingSPR sensor and multimode online transmission optical fiber SPR with boric acidpolymer polymer surface modification are built. The experimental data processingmethod are studied.Gold nanoparticles are prepared and fixed with experiments.