Study On Low Voltage-Driven Capillary Electrophoresis Chip Based On Optical Fiber Coupled

Capillary electrophoresis chip (CE chip) has become a new microanalysis instrument in recent decades. It has many advantages of rapidness, high-efficiency, little reagent and has been widely used in DNA analysis and array testing, amino acid and protein separation and biology cell research. However, CE chip needs high voltage power during sample injecting and separating process, and optical structure of the confocal LIF detection system is complicated, which limit the microminiaturization and integration of CE chip. So the study of low voltage-driven CE chip based optical fiber coupled is discussed in this paper.The low voltage-driven arrayed electrodes and optical fiber channels were integrated in one chip in this paper. Pt electrodes were sputtered on glass substrate with the Micro-Electro-Mechanical System (MEMS). Micro channel and optical fiber channels were etched on glass cover, the substrate and the cover were packaged by fusion bonding. In the part of low voltage control, voltage control circuit of the electrodes was designed with EPF10K20TC144-4 chip as control core. The software programme of hardware circuit was accomplished using Verilog HDL. UART between the computer and FPGA chip and circulation voltage control was accomplished. Large numbers of bubbles were formed during the injection and separation for low voltage-driven arrayed CE chip, which badly block electrophoresis analysis, so elimination of the bubble was studied emphatically. Water glass, polyimide and Si₃N₄ were fabricated on the electrode substrate. The package technics of the low voltage-driven CE chip with insulated film was studied based on a great deal of experiments.CE chips with different insulated film were tested. The experimental results indicate that Si₃N₄ can restrain the bubble formation effectively, and the sample injection and part separation can be accomplished. The cover with optical fiber channels and glass substrate were bonding, which was used to analyze Rhodamine B, and the good electropherogram can be got. The results validate that the low voltage-driven CE chip based optical fiber coupled can be used to analyze the sample with LIF detection.