整合液體介電泳及毛細管電泳晶片之研究

Abstract

本實驗利用液體介電泳力形成無邊壁之虛擬毛細管流道並在其中進行毛細管電泳分析，進一步調控兩個互相垂直的電場觀察電滲流流速改變情形，並且嘗試利用此一平台完成不同電性粒子分離及DNA分離。 在兩板間施加一100 kHz、80 Vrms之交流電時，含有20 mM Borax和5 mM SDS緩衝液將會依照下板電極形狀，形成一寬度500 um、長度3 cm、高度 25 um之虛擬流道，接著在此流道兩端施加一直流電場進行電泳分離，當兩端施加電場為26.67 V/cm時，利用電中性粒子觀測到最大電滲流流速為219.39 um/s，此外當我們調控兩板間交流電給予一直流偏壓，亦會觀察到泳速提升現象，而在分離應用方面，開發出數位十字進樣法，成功將樣品注入到流道之間，更進一步完成分析物的分離試驗。

In this study, we propose a capillary electrophoresis (CE) in a wall-less liquid dielectrophoresis (LDEP)-formed virtual microchannel. And further, two perpendicular electric fields are manipulated individually to effect the electroosmotic flow (EOF). The different charged particles and DNA are separated by utilizing the chip. When a 80 Vrms and 100 kHz signal was applied, the liquid containing 20 mM borax and 5 mM sodium dodecyl sulfate (SDS) was pumped into the virtual microchannel by following the electrode pattern on the bottom plate. The dimensions of the DEP-formed microchannel were 500 um in width, 3 cm in length, and 25 um in height. Then, a DC electric field is applied along the virtual channel to execute the electrophoresis process. The EOF at the velocity of 219.39 um/s is achieved when the applied DC electric field is 26.67 V/cm. Besides, while increasing the LDEP AC electric field with a DC bias between top and bottom plate, the EOF increased spontaneously. A digital cross-channel injection system is successfully demonstrated and integrated into the chip. By this system, the sample can be injected into the main channel and separated by CE process.