利用絕緣結構介電泳進行螢光蛋白質檢測

Abstract

在本論文中，我們以絕緣結構介電泳作為出發點，利用其特性分離的不同粒子，並使用這個方法進行螢光酵素免疫反應。絕緣結構介電泳能夠在一個晶片上用特定的電訊號控制特定物體。我們運用黃光微影製程製作出一種新型的SU8介電薄膜，並在這片介電薄膜上進行絕緣結構介電泳。當我們施加100 kHz的電訊號時，1 μm的聚苯乙烯球會進入SU8薄膜孔洞中，反之，5 μm的粒子則會遠離孔洞，進而成功地分開兩種粒子。利用這樣此特性，在粒子上修飾Biotin，然後讓粒子與Streptavidin相結合三分鐘，並同時進行絕緣結構介電泳使得粒子可以集中在孔洞中，最後以螢光顯微鏡觀察反應結果。本實驗中，我們最低可以偵測到1 μg/mL的蛋白質濃度。本論文成功運用介電泳將兩種不同粒子分離，並且也成功的在三分鐘內完成螢光蛋白質檢測反應，偵測之濃度約為1 μg/mL，並發展出快速的螢光蛋白質檢測晶片。

We fabricated a 200-μm-thick PMMA and a 50-μm-thick SU8 film containing microholes to deform applied electric fields. Insulator-based dielectrophoresis (iDEP) was demonstrated through the films to separate particles of different sizes by applying an appropriate electric signal. Two water droplets were placed above and beneath the film, and the top one contained mixtures of 1-μm and 5-μm polystyrene beads. When applying a proper AC signal, 1-μm beads were concentrated and deposited in the microholes, while 5-μm beads were expelled from the microholes by the iDEP forces. The particle collection was further employed to realize detection of fluorescent labeled strepavidin by biotin-conjugated polystyrene beads. Biotin-conjugated polystyrene beads were first mixed with the fluorescent labeled streptavidin for three minutes. After streptavidin was captured by biotin-conjugated particles, DEP signal was applied to collect the particle into microholes. The intensity of fluorescence was measured by fluorescence microscopy. Currently, 1 μg/mL strepavidin was successfully detected.