Study On Imaging Interferometry For SPR Microarray Detection

High-throughput Surface Plasmon Resonance (SPR) microarray detectiontechnique, which is a powerful tool for the study of proteomics and drug discovery &development, is currently a hot research topic. In this thesis, imaging interferometryfor SPR microarray detection is studied systematically. Not only the basic theory ofcommon-optical-path SPR microarray interferometry is described, but the problemsin designing SPR interferometer based on spatial phase modulation and phaseextraction algorithm are carefully studied. With experimental study, measurementerror is analyzed. Furthermore, phase shifting interferometry for SPR microarraydetection is presented and studied. Based on the SPR biosensor model and Fresnel formula, numerical simulationand analysis is carried out so that the characterization of SPR phase detection isachieved. Combined with the phase property of SPR, the theory of polarized lightinterference and modern interferometric phase measurement technique, acommon-optical-path polarization interferometry for SPR microarray detection ispresented and its special character is inferred. In order to implement the SPR microarray imaging interferometric systembased on spatial phase modulation, some problems such as light source intensityuniformity, resonant angle adjustment, optical path compression and spatial carrierfrequency determination are solved. After the interferometer being produced andassembly work being finished, it is ready to work. After the system demand and specialty of SPR interferometry based on spatialphase modulation phase extraction algorithm is analyzed, Spatial Phase Detectionmethod is used for SPR microarray interferometer. The systematic error caused by thealgorithm itself is studied and an adapted one, Initial Phase Stepping Spatial PhaseDetection method is proposed. Simulation result shows that if the signal to noise ratioof the system is 20 dB, phase detection error's standard deviation reduce 0.68° usingnew algorithm than the old one. Further, the application program for theinterferometer is programmed, which can detect 4×4 SPR array at the same time. -II-Abstract Experimental study, including phase array measurement, environmentalinfluence test and short time stability test are performed. Measurement error isanalyzed with suggestion for system improvement being concluded. At last, common-optical-path phase shifting interferometry for SPR microarraydetection is presented and analyzed and systematic theoretical design using thismethod is performed. The measurement error of phase shifting method is calculated.It is concluded that if 5 frames are used per time, in order to achieve 0.3° precision inphase measurement, phase shifting error must be limited in± 0.1° plus at least 60dBsignal to noise ratio. The research result will be guidelines for practical systemdesign.