表面電漿共振移相干涉術(surface plasmon resonance phase-shift interferometry，SPR-PSI)是結合表面電漿共振與移相干涉術來檢測微陣列(microarray)生物分子在固體與液體或固體與氣體界面間發生交互作用時，造成界面上之介電常數或厚度微小改變，反射光波相位空間變化情形；利用此方法來分析生物分子間的交互作用(biomolecular interaction analysis，BIA)，可不需對生物分子做任何的標記(labeling)，直接即時地偵測如此便可大大的縮短檢測的時間，改進了螢光檢測方法之無法定量的困擾，以及螢光標記後信號隨時間衰減的問題。 本論文提出一有別於的其他SPR影像系統的檢測方法，主要以改良式的Mach-Zehnder移相干涉術為主，配合五步還原演算法來觀測共振角下，反射光波之空間相位因表面電漿共振特性隨界面微量改變而造成的相位漂移(phase drift)情形。本系統具有即時地、靈敏度高以及大量平行篩檢(hight-throughput screening)等優點，可預期將被廣泛應用於各類生物分子檢測的領域上。 目前，除了表面電漿共振角搜尋可精確到 度外，對於不同氣體可靈敏地量測到折射率變化量為 2.5×10^-7，其共振相位計算穩定度可達π/100，空間相位的穩定度更可達到π/500；在DNA的量測方面，可初步地判別長度為5-mer的DNA於SPR感測器表面上的吸附情形。 Surface plasmon resonance phase-shift interferometry (SPR-PSI) is a novel technique based on SPR and modified Mach-Zehnder phase-shifting interferometry to measure the spatial phase variation of a resonantly reflected light in biomolecular interaction between the solid and liquid interferences. This SPR-PSI system with high resolution and high-throughout screening capability can provide biomolecular interaction analysis (BIA) in real-time and can observe DNA microarray hybridization without additional labeling. Owing to the feasible and swift measurements, the SPR microarray biosensors can be extensively applied to the nonspecific adsorption of protein, the membrane-protein interaction, receptor-ligand interaction, and DNA hybridization. The SPR-PSI system measures spatial phase variation with a five-step algorithm to calculate the phase variation of interferograms. Currently, the SPR-PSI system can achieve the detection limitation of 2.5×10^-7 of refractive index, the long-term phase stability of π/100 , and the spatial phase resolution of π/500 in SPR angle. The SPR-PSI system with its DNA microarray has been successfully used to diagnose the adsorption of 5-mer probe ssDNAs in biosensor interference according to measure the spatial phase variation.
