A microsystem of low-voltage-driven electrophoresis on microchip with array electrode pairs for the separation of amino acids.

In this paper, a new approach for the separation of amino acids on the electrophoresis chip-based low-voltage-driven electrophoresis was reported in detail. This low-voltage-driven electrophoresis process could be realized by powering directly the arrayed electrode pairs with low direct current (DC) voltage to generate a moving electric field along the separation microchannel, which could maintain enough electric field strength for electrophoresis. The proposed microfluidic electrophoresis chip was bonded directly with silicon-on-insulator (SOI) substrate and polydimethylsiloxane (PDMS) cover plate at room temperature. The microfluidic channels and the arrayed electrodes were etched on SOI wafer by silicon microelectromechanical system technology. A specially integrated circuit was proposed to power a 30-60-V DC voltage to particular sets of these electrode pairs in a controlled sequence such that the moving electric field could be formed, and the low-voltage-driven electrophoresis could be realized in the microchannel. In the experiments, with 10(-4) mol/L phenylalanine and lysine as analytes, the separation of amino acids on the low-voltage-driven electrophoresis microchip was conducted by homemade integrated control circuit; a method for separating amino acids was well established. It was also shown that the phenylalanine and lysine mixture was effectively separated in less than 7 min and with a resolution of 2.0. To the best of our knowledge, the low-voltage-driven microchip electrophoresis device could be of potential prospective in the fields of integrated and miniaturized biochemical analysis system.