An integrated PDMS electrophoresis microchip with LED induced fluorescence detection

A PDMS electrophoresis microchip, which integrated with optical fiber for fluorescence detection, was fabricated by using silicon master. A deep reactive ion etches (DRIE) technology was used to fabricate the silicon master with positive features. The PDMS replica was fabricated by casting PDMS prepolymer against the silicon master, where an optical fiber was first fixed on the end of separation microchannel. To improve the rigid characteristics of integrated PDMS microchip, the chips were subsequently assembled by reversible sealing against glass plate. A blue light emitting diode (LED) was used as excitation light sources for inducing fluorescence detection through coupling LED light into the optical fiber. As an application, integrated PDMS microchip was tested in the capillary electrophoresis separation of DNA markers. The results showed that DNA markers could be effectively separated and detected except for the segments of 271 and 281.