The Fabrication Of Detection System Based On The Integrated Fiber Capillary Electrophoresis Chip

The research on capillary electrophoresis detection system now represents the developing direction in analysis instruments field. The analysis system based on the integrated fiber capillary electrophoresis chip which can detect the biochemical molecules and ions, is an integrative platform for biochemical analysis and has multiple functions such as injection, separation and detection etc. The paper presents the miniature detection system, which is correlative with the integrated fiber capillary electrophoresis chip. The research contents contain the principle, structure and application examination of the detection system.In the detection system, the blue LED was used as the exciting light source and the PMT was used as the optoelectronic converter. To avoid the interference of stray light outside the system, the structure of double darkroom was adopted. The novel fiber coupler made the experiment operation easily. Four high voltage power supply modules were used in the detection system, and the sample in the separation channel could be controlled. The relay array was used to realize circuit switch; the AT89C52 was used as the microcontroller to control the work of every component and the serial interface circuit was used in the data traffic and the high-precision ADC was used in the data acquisition. Using the Visual Basic 6.0, the control software, which can add, delete, modify and save the data was presented, and it has the functions such as automatic circuit switch, count down, 10 program setting steps and the separation voltage, PMT voltage can be controlled respectively. The size, mass, response and sensitivity are 242mm×60mm×240mm, 2.5kg, respectively.The experiment of pinched sample loading was implemented in the detection system and the phenomenon that sample could be controlled in the separation channel was proved. A mixture of four amino acids (arginine, phenylalanine,glycin,aspartic acid) labeled with fluorescein isothiocyanate(FTTC) was separated in the detection system, the separation voltage is 250V/cm, the separation time is less than 150 seconds. The repeated experiment of four amino acids indicated that the RSD of the three parameters: peak area, peak height and repeatability of transport time were 4.7%, 2.2% and 2.8%, and the reliability of the detection system was proved. The separation experiment of the mixture of (?)X174/HaeIII DNA and the PCR products of SARS virus indicated that the detection system could separate completely the DNA segment no less than 10 bp under the condition of 1100V.