Performance Analysis And Chip Electrophoresis Process Research Of Electrophoresis Chip In Low-voltage-driven Mode

Miniaturized total analysis system (μ-TAS) is based on Micro Electronic Mechnical System (MEMS) fabrication technology, which coupled with analytical chemistry and biochemistry, and integrated analytical process on microchip to make the whole analytical system miniaturized, integrated and portable from sample preparation to detection. Chip-based electrophoresis is termed as the miniaturized analysis technique that performing electrophoresis and detection in micro channels etched on microchip. Low voltage electrophoresis chip makes the separation voltage low by laying the micro arrayed-electrodes in the sidewall of the channel. This chip can provide the electric field intensity which electrophoresis needs in low voltage. It avoids the shortcoming of security and big size in high voltage power supply what makes the chip system for integrated and packed. The paper focuses on the design and electrophoresis of the low voltage chip, low voltage chip electrophoresis system establishment and discussing the electrical properties and separation ability.Firstly, silica-PDMS CE-chip was designed and fabricated, of which the electrical characteristics concerning insulation and electroosmotic flow and as well the linear range of voltage-current curve were discussed. The operation and detection parameters were optimized according to the electrical characteristics of microchannel and properties of amino acids sample system, so as to validate the possibility of applying these chips to perform effective analysis. With the optimized operation parameters of amino acids, sodium borate running buffer was prepared to 5mmol·L-1,pH=9.0, injection field strength was set to 200V·cm-1 for 10s loading, separation electric field intensity was 100 V·cm-1, which resulted in a resolution 3.14 of two amino acids.The low voltage chip electrophoresis system was consisted of control system,silica-PDMS chip and detector. On the system for the separation of amino acids,injection time, voltage, voltage application mode and voltage switching time were discussed. The amino acids can be separated completely with the optimal conditions, which the mode double voltage imposed, injection time of 10s and separation voltage of 60V. Through drawing and calculation, some methods concerning voltage switching time set-up were obtained.According to protein separation results by capillary electrophoresis, the mobility between Lysozyme and bovine serum albumin is large difference. Therefore, separation of the Lysozyme and bovine serum albumin is relatively easy theoretically. However, the separation effect is not satisfactory in low voltage chip electrophoresis. Many factors, such as buffer type and concentration, protein adsorption and voltage parameter settings, will affect the separation. The next step in the work is optimizing the parameters in order to obtain better results.