The Research Of Capillary Electrophoresis System Based On Integrated Optical Fiber

CE (Capillary Electrophoresis) is a kind of liquid-phase separation technique which use capillary as the separation channel, high-voltage electrical field as the driving force. Microfluidic CE chips transfer the traditional CE to chips, completing sample injection, reaction, separation and detection on chips. Compare with traditional CE, microfluidic CE chip has great advantages of low-cost, high efficiency and simple operation. In this paper, research on the design and process of microfluidic CE chips was included. Based on the CE chip, laser-introduced fluorescence detection system was established. In addition, the integration of CE chip and PCR chip on one chip was discussed, in the hope of integrating the sample duplication, separation and detection on a single chip, which was the research trend of microfluidic chips.The system was consisted of five parts, the main part is the three-layer structure of PDMS+PDMS+Glass microfluidic CE chip, which had simple processing flow and close bonding, meanwhile, its design can effectively reduce the sample negative phenomenon and ensure the optical fiber center completely aligned with the channel. In addition, optical system, voltage source system, signal conversion and amplification system were also included. In the detection system, the blue LED was used as the exciting light source and the PMT was used as the optoelectronic converter. The data was collected by PXIe-6124 data acquisition card. Using this detection system, a mixture of three amino acids (Gly, Phen and Arg) labeled with FITC was separated within 130s.The paper was consisted of the following parts: 1 The principle of microfluidic CE chips and the latest research in this filed was introduced.2 Simulation under various sorts of micro-channel shapes and injection methods was conducted by CoventorWare. Based on the simulation analysis, a three-layer CE chip was designed with related parameters optimized.3 Improvement was made to manufacture process of microfluidic chips. Soft lithography method was used to fabricate the PDMS caps which contained the micro-channel while deionized method was used to realize the package of caps and substrate.4 Integration of CE and PCR onto a chip was discussed and related simulation of micro-devices was completed. Based on the simulation results, a PCR-CE chip was designed and fabricated.5 A detection system based on the fiber integrated microfluidic CE chip was established. The separation time of a mixture of three amino acids (Gly, Phen and Arg ) labeled with FITC decreased to 130s.