Basic Research Of Microchip-based Capillary Electrophoresis

This report mainly focuses on the basic research area of the microfluidic systems,which is listed as follows.Several types of home-made microfluidic devices were built up in the laboratory,including one microchip-based laser-induced fluorescence (LIF) detection systemwith four fluorescent channels, two LIF detection microfluidic devices with pulsedlaser or consecutive laser as light sources, respectively.The qualities of home-made glass microchips were evaluated. The sieving matrixwith ultra-low viscosity was applied to the performance of microfluidic chips.Different separation conditions were estimated, especially the factors of additive,concentration, electric field strength et al. The mechanism of the separation wasdiscussed as well. The sieving matrix has a very low viscosity almost equal to that ofwater, which is particularly suitable for use in microfluidic chips because this factorassures relatively easy and rapid operation.The qualities of home-made injection-molded PMMA microchips were alsoevaluated. Dynamic and static surface coating methods were set up to modify theinner surfaces of PMMA microchannels. For the dynamic coating, differentsurfactants were added to the running buffer to control the direction and magnitudeof electroosmic flow (EOF) in the PMMA microchannels. By applyingphoto-initiated polymerization methodm, the inner surfaces of PMMA microchipswere modified. EOF was suppressed almost to zero and the hydrophilicity wasstrongly increased. The efficiency and reproducibility of the separation weredistinctly improved as well.