Developed Based On Evanescent Wave Fiber Optic Biosensor Probe

Fiber biosensor is a kind of microanalysis technique which can be used in long distance and real-time analysis with high sensitivity. It has huge potential in test of water, food and biological agent. The philosophy of measurement is to confirm the attribute and contents of zoetic substance by testing the excited fluorescent in antigen antibody reaction between zoetic substance in the liquid and the mark substance on the probe . Fiber probe directly effects sensitivity and veracity of the whole facility. Therefore, the foundation of fiber probe and the research of action mechanism become the chief task and key problem in research of the whole fiber evanescent biosensor. Based on the research of principle and structural of fiber evanescent biosensor, the impact of taper probe on fluorescence detect and transmit is researched by analyzing light transmitting theory and light wave theory. On the one hand, by analyzing close condition of each kind of modes, a conclusion is proved that after the probe is modified by mode match theory, the mode transmitted in uniform sensitive part will not be cut in transmit area. By analyzing the impact of probe radius on close condition, an idea is put forward that minishing taper radius can enhance close frequency to make high rank light pass. On the other hand, by analyzing the relationship between evanescent depth and angle of incidence and the relationship between angle of incidence and position of incidence, a model with parabola shape is set up and the following conclusions are achieved: to maxmium the exciting energy in uniform sensitive part, the angle of incidence in taper sensitive part should decrease monotonously and the angle at the end of taper should be equal to critical angle. By modifying the shape of taper, angle of incidence can be more close to critical angle and stronger evanescent wave can be excited. These conclusions provide academic guidance for the research of fiber evanescent biosensor.The designing, optimization and produce is achieved and correlation inspect is introduced into the system. Fiber biosensor system is constructed with fiber entirely. Experimentation results show that this system can inspect the solution with the concentration of 0.01nmol/L and can meet the need of high precision in real zoetic substance test, which provides stable groundwork for inspect in immunity analysis method. The whole system works stably, has strong anti-jamming and has small and simple structure, which is suitable for locale inspect.