以Mach-Zehnder移相干涉術(phase-shift interferometry, PSI)為基礎的嶄新表面電漿共振(surface plasma resonance, SPR)影像系統,可即時地獲得因DNA雜交(hybridization)所導致反射光的相位差。這個SPR DNA微陣列(microarray)檢測技術,不需額外的標記(label-free)即可在DNA雜交過程中檢測出DNA的雜交反應量。由實驗結果顯示SPR PSI影像系統的偵測極限約為1pg/m平方公尺的生物分子的表面覆蓋度,超過傳統SPR影像系統的禎測極限數百倍。因此,SPR PSI影像系統結合SPR DNA微陣列,可以提供即時地分析DNA雜交的情形,並同時具有超高解析度及大量平行篩檢(high throughput screening)的特性。
The novel surface plasmon resonance (SPR) imaging system based on modified Mach-Zehnder phase-shifting interferometry (PSI) measures the spatial phase variation of a resonantly reflected light during DNA hybridization. in this technique, the SPR DNA microarray can diagnose the target DNA without additional labeling in the real-time DNA hybridization analysis. Experimental results demonstrate that the detection limit of the SPR PSI imaging system is improved to about 1 pg/mm^2 surface coverage of biomaterial for each individual spot over that of the conventional SPR imaging system. Therefore, the SPR PSI imaging system and its SPR DNA microarray can provide the capability to analyze DNA hybridization in real-time, with high resolution and at high-throughput screening rates.