Fabrication of DNA purification microchip integrated with mesoporous matrix based on MEMS technology

This paper presents a novel microfabricated DNA purification microfluidic chip with enhanced performance based on the principle of micro solid phase extraction. The microchip comprises a layer of mesoporous material as solid phase matrix which is fabricated on the internal wall of the channel of microfluidic chip by electrochemical etching Si in an electrolyte. The conditions of electrochemical etching and porosity of the mesoporous matrix have been investigated. The properties of mesoporous matrix have been characterized by scanning electron microscopy and by BET (Brunauer, Emmet, and Teller) nitrogen adsorption analysis. The pore size of the mesoporous matrix is in the range of 10–30 nm, and the surface area is about 300 m²/g. Compared with the microfluidic chips with micropillar array matrix or non-porous matrix, the microchip with mesoporous matrix is able to extract enough polymerase chain reaction-amplifiable DNA from cultures of rat mesenchymal stem cells in 20 min. This highly efficient, effortless, and flexible technology can be used as a lab-on-a-chip component for initial biologic sample preparation.