Microfluidic Chip Control Analysis Of Laser Induced Detection Of Fluorescent Microspheres,

The topic of this thesis is mainly focused on the application of Laser Induced Fluorescence (LIF) System detecting 5.6μm microspheres delivered on disposable microfluidic chip. The designing detail and experiment result is presented, proving its superiority over conventional cytometric application, for its separation of detecting and fluidic system.The application of fluorescein tagged microsphere in LIF detection is the novel research approach in medical and biological area, which is generally based on cytometric technology. In this thesis, the 5.6μm microsphere is delivered by means of "sheath flow", passing through the optical detection zone on the microfluidic chip. A confocal optical theme is employed to form the LIF system. The parameters of the optical system are optimized to validate fluorescent interaction with single microsphere, and the optical sectioning power is configured to be compatible with the structure of microchannel. Under experiment verification, the lowest fluorescein (R-phycoerythrin, R-PE) detection limit of this optical system is 0.45nMol/L, corresponding to 122 molecules in valid detection region. The signal to noise ratio of single fluorescent microsphere detection is 58.9, which is sensitive enough for instrumental detection.Under the concept of "Micro Total Analysis system (μ-TAS)", we introduced the development of LIF detection on microfluidic chip in chapter I, and described the theoretical model of the system in chapter II. The detailed design and optimization of optical detection system is presented in Chapter III, and the optical performance is evaluated by experiments in Chapter IV. A conclusive and periscopic discussion is presented in Chapter V.