The Mechanism And Experiment Of Protein Detection Based On Optical Fiber Sensing

Biosensor which combines biological sensitive materials and proper chemical transducer is a testing device. It can detect the variation of physical, chemical or biology quantity. Now, it plays an important role in many fields, such as, medicine, fermentation, food, and environmental monitoring. The biosensor based on TFBG-SPR using the change of the evanescent field’s effective refractive index to realize the detection. The change is caused by the bond of the material under test and the molecular membrane. The TFBG-SPR biosensor can improve the sensitivity of the sensor and reduce the sensor’s size. The rapid detection of protein biosensor is a very important purpose. In many cases, the protein which needs to be detected has a few quantities and need detect rapid and continuous. The TFBG-SPR biosensor is very suitable for this situation.This paper introduces the relevant theoretical knowledge, such as, coupled-mode theory of tilted fiber Bragg grating and the surface plasma resonance technology. The detection principle of TFBG-SPR biosensor is described. The further discussion according to the protein molecular probe was done. We demonstrate the possibility of protein molecule probe which based on TFBG-SPR. In experiments, the method how to make a protein molecule probe is introduced and the way how to collection and storage experimental data is introduced, too.Refer to a large number of domestic and foreign literature, comprehensive consideration of the requirement of reagents, experimental environment and conditions, the time needed for experiment and protein fixed effect, the method to fix the protein on the surface of the gold film is finally chosen After then, the process of data collection and storage in the whole experiment was introduced, including equipment output data format and the PC software writing. And finally, the datas of all tests in the process of experimental are analyzed.In the process of fix cysteamine hydrochloride on the gold-plated TFBG surface, we can clearly observe the change of TFBG transmission spectrum cladding mode’s light intensity and wavelength obviously. This prove the sulfydryl in cysteamine hydrochloride aqueous solution reacts with gold film produce Au-S bond.IgG antigen repeatedly fixed also cause the change of the cladding mode. Finally, the continuous change of cladding mode in the process of IgG antigen-antibody reaction verifies the feasibility of TFBG-SPR biological molecular probe. The protein quality used in whole experiment is very little. Except that, as a result of the antigen antibody specificity recognition characteristics, the sensor can also be made of this nature, too.From the theoretical analysis and experimental results, TFBG-SPR protein probe can basically meet the practical application of biosensor. It has a low cost, miniaturization, specific requirement and higher sensitivity. Because of these advantages, the TFBG-SPR protein probe has good prospects for development.