近年來，螢光共振能量轉移的相關應用越來越受到重視，因其不僅能夠實現分子檢測，也能了解特定分子間的交互作用。然而實際應用時FRET訊號仍是相當微弱且須花很長的時間來檢測。又由於使用的螢光供體為奈米等級的量子點，這使得分子的操控上又更加困難了。本文我以交流電荷動力作用為基礎來開發具有實現快速增強FRET訊號功能的微流控平台，藉由交流電滲流(AC Electro-Osmosis, ACEO)微漩渦及介電泳的輔助來匯集QD並固定於電極上形成緊密的自組裝結構，接著再將目標單股DNA(single stranded DNA, ssDNA)集濃並捕捉到事先匯集好的QD來增益FRET檢測。結果顯示在一開電場的瞬間可以立即看到明顯FRET訊號的增強，表示QD及目標ssDNA的鍵結速率在ACEO的作用下可以在30秒之內迅速提升。此方法也相當靈敏，在不使用APD的情況之下，ssDNA濃度低至0.16 pM仍可以測得到。這樣的微流控平台可以針對目標或特定分子實現快速偵測及辨識，故對於設計生物晶片以進行有效生醫診斷的開發有很高的開發潛力。
在本文的第四章，我先演示了以陣列式的60微米城垛式電極利用ACEO分開捕捉QDs及ssDNA並探討ACEO的捕捉機制，從中評估粒子的集濃倍率。結果發現到QDs在一開啟電場後就立即被捕捉到電極中心及邊緣，其中，邊緣區的結構較緊實，我認為是介電泳(dielectrophoresis, DEP)及電場誘導偶極( field induced dipole attraction, FIDA)的加成作用，使得粒子聚集的更緊密。同樣地，ssDNAs也能以同樣的方式捕捉到電極區，但電極邊緣的聚集並不明顯。從本章的結果來說，我成功地使用微米電極實現奈米粒子的捕捉。
在本文的第五章，我開始進行FRET檢測，利用ACEO先集濃QDs，利用QDs集濃後會吸附在電極表面的特性，先將QD溶液洗掉後再加入ssDNA溶液來進行FRET。結果在一開啟電場後，立即可以測到快速且明顯的FRET訊號，而且，在目標ssDNA濃度為16 nM時，其FRET效率也與理論值10.6%接近。然而，我也發現到FRET訊號之中會參雜靜電吸附的假訊號，會干擾到實際的FRET訊號，這使得靈敏度無法繼續提升。
在本文的第六章，我先調降了ssDNA探針的濃度，降低假訊號的干擾，另外，我也發現在城垛式電極的FRET訊號強弱會隨著區域不同而不同，訊號大小為:T字形區域>內部邊緣>中心區，而我認為T字形區的訊號最高的原因是其粒子的集濃效果最好，這是來自於不對稱電極造成的額外淨流動，DEP和FIDA皆在T字形區輔助ACEO的匯集，而且已聚集好的分子不會被帶走，使得T字形區的聚集結構更加穩定且不容易被破壞。於是我改用T字形區域來進行FRET。最後發現到隨著Target ssDNA濃度的降低，FRET訊號有下降的趨勢，且濃度可下探至0.16 pM。

Fluorescence Resonance Energy Transfer (FRET) is a widely used technique for probing target molecules or specific molecular interactions. However, it might suffer weak FRET signals and long detection time. In this thesis I develop a new microfluidic FRET sensor to overcome the above shortcomings. The FRET sensing is made by probing target ssDNAs by quantum dots (QDs). I apply the joint effects of AC electro-osmosis (ACEO), dielectrophoresis (DEP) and field induced dipole attraction (FIDA) to trap nano-sized QDs and ssDNAs. I find that our sensor can not only amplify FRET signals after turning on fields, but also push the FRET detection limit to 0.16 picoM without using a highly sensitive photodetector like avalanche photodiode (APD). Therefore, it will have a great potential to capture and detect desired biomarkers in dilute solutions, opening up a new avenue for more efficient and accurate medical screening and molecular assays at chip scales.

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