Design Of Optical Fiber Surface Plasmon Resonance Spectrometer And Research Of Detection Algorithm

The characteristics of surface plasmon resonance(SPR)detection technique are high sensitivity,real time,and the sample do not need to be labeled and purified.So it is widely applied in biochemistry,life sciences and other fields.Optical fiber SPR sensor use optical fiber as the carrier for SPR effect excitation,with a strong anti-electromagnetic interference capability,high security,and easy to be integrated because its small size.At present,most of the commercial testing instrument of SPR are using prism type SPR sensor.Prism type SPR spectrometer deficient in remote detection and real-time,while the fiber-type spectrometer SPR can solve this problem.This paper aims to research and develop an optical fiber surface plasmon resonance spectrometer.And the main works and achievements include:1.An optical fiber surface plasmon resonance spectrometer have been designed and constructed,including: the module of sample injection,the temperature control module of sensing zone and spectrum acquisition module.Also the corresponding control and data processing software for process control,parameter setting,signal acquisition,data analysis and other operations have been wrote and optimized.2.Since the noise of the spectrum of optical fiber surface plasmon resonance is mainly Gaussian noise,this paper presents the Wavelet Threshold Method for signal denoising.This paper choose symlet11 wavelet as the mother wavelet.To measure the influence of different threshold rules and decomposition level on filtering,the root mean square error(RMSE)have been chosen as an index.The optimal parameters of the wavelet threshold method have been acquired,and the process of signal preprocessing have been completed.3.The spectrum of optical fiber surface plasmon resonance shows the characteristics of wider full width at half-maximum(FWHM)and smaller peak value.This paper presents a method to process the SPR signal based on the Gaussian Fitting.Combined with the trust region algorithm to determine the Gaussian fitting function,and then the resonance wavelength be calculated by line search method.Data processing of standard spectrum of glycerin with different concentration proves that this algorithm can adapt to optical fiber SPR spectrum characteristics,and calculate resonance wavelength accurately.Through the optical fiber SPR spectrometer presented in this paper,the experiment of calibration of concentration of sucrose solution and the experiment of antibody immobilization on the surface of sensor have been conducted respectively.The results shows that the optical fiber SPR spectrometer presented in this paper has good performance and high sensitivity.All of the works can provide a meaningful reference for future analysis.