Fluorescence Detection System For Microfluidic Chip Developed

Microfluidic chip, which is also called integrated capillary electrophoresis (ICE), planar, capillary electrophoresis (CE) chip, is used in the biochemical analyses such as DNA sequencing and the separation of the protein or monoplast. As compared to the conventional capillary eletrophoresis, it shows many advantages: less reagent, minitype, high efficiency and sensitivity. We develop a laser induced fluorescence (LIF) detection system for use with the ICE chip, which is based on a 488nm argon ion laser and FITC fluorescent dye.Optimization of the LIF detection system is the key of commercialization and utilization. Therefore, we analyze the effect of various factors on signal-noise ratio in LIF detection system. Then we set up adjustable mini LIF detection system of transmission style and reflection style, which are consist of optical module, mechanical module and electronic module. In this detection system, the excitation laser beam from the argon ion laser illuminates some point that lies in the separation micro channel. Then the fluorescent signal is emitted when the fluid that contains FITC dye flows through the point. After that, an objective lens collects the optical signal and transmits it to the Photoelectric Multiplier (PMT). Finally, the signal is sampled and the electropherogram is displayed on the computer screen. The results of the experiments match the theoretical conclusions. Furthermore, they let us know the relationships among the laser, the size of pinhole, the objective and the signal-noise ratio more clearly. So we improve our detection system by changing its structure, the parameter of components and the circuit.This paper includes six chapters. Chapter one gives a brief introduction of microfluidic chip and its detection methods. Chapter two explains the mutuality theory about the detection of microfluidic chip, including confocal theory. Chapter three introduces each module in our experimentation system, including optical module, photoelectric conversion module, and electronic module. Chapter four is about the results of these experiments. Chapter five shows the shortage of our system and gives the corresponding advices.to improve it thrbugh the aspects such as objective, pinhole, filters, circuits and so on. Chapter six sums up this paper.