增強螢光訊號偵測之靈敏度

Enhancing Fluorescence Detection Sensitivity

因受激輻射之同調性，應用破壞性干涉可大幅增強受激輻射之螢光偵測訊噪比，從而降低染料分子濃度的可偵測極限。我們實現了結合鎖相放大器以及破壞性干涉儀之激發－探測實驗，並以受激輻射為對比，達成了長工作距離的螢光成像功能。實驗結果顯示可經由破壞性干涉將探測光束的強度降低10倍，而仍維持良好的訊噪比，這代表可偵測的染料分子濃度亦可以降低10倍。受激輻射之同調性，讓此技術具有發展高解析3D同調光學相干斷層掃描成像的潛力，於組織成像形成獨特的對比。 Destructive interference greatly improves the signal-to-noise ratio of fluorescence detection based on stimulated emission, and thus decreases the detection dye concentration limit. We established SE-based detection in longworking- distance settings by implementing pump-probe method with lock-in detection and destructive interference. Results show that we were able to achieve 10 times intensity ratio decrease in the probe beam with destructive interference, which corresponds to 10 times decrease of concentration detection limit. We are now developing the technique’s potential for high-resolution 3D biological imaging by stimulated emission optical coherence tomography(SE-OCT) , using SE fluorescence as a viable and unique contrast.