Fabrication of Solid Phase Extraction DNA Chips Based on Bio-Micro-electron-Mechanical System Technology

In this work, a novel solid phase extraction (SPE) deoxyribonucleic acid (DNA) microfluidic chip with silicon-PDMS-glass structure was fabricated based on bio-micro-electro-mechanical system (BioMEMS) technology. Four kinds of solid phase matrixes were fabricated on silicon substrates, and the characteristics of these matrixes were analyzed. The porous oxidized silicon was optimally selected as the solid phase matrix for purification DNA (deoxyribonucleic acid). The different sealing technologies were contrastively developed for sealing the chip to form a close channel. The polydimethylsiloxane-glass (PDMS-glass) cover was fabricated using the optimal pressing method and the silicon substrate with the solid phase matrix was bonded with the PDMS-glass cover to accomplish the preparation of the SPE chip. This SPE chip was used successfully for purification genomic DNA from the rat whole blood. DNA of 23.5ng was extracted from per microlitre whole blood and the extracted DNA was successfully amplified by PCR, which could reach the level of the commercial DNA purification kits. Furthermore, the SPE microfluidic chips have the potential to be integrated with other sample preparation microchips, PCR microchip, capillary electrophoresis microchip and so on to achieve detection and analysis of the complex biological samples.