| Capillary electrophoresis (CE), with its low cost, small analyte consumption, low pollution, short analysis time, high efficiency and high sensitivity, has become one of the most powerful analytical methods. It meets the increasingly critical requirements of separation and analysis of complex samples in varies fields such as medicine, environment and life sciences. CE with laser induced fluorescence (CE-LIF) is one of the most sensitive detection methods, however, some weaknesses of the laser, such as the bulky volume, expensive cost, limit of alternative excitation wavelength and so on, restrict its development and application. Using the high-power light-emitting diodes(LED) as excitation sources of fluorescence detection can rapidly reduce the cost and the volume of detection, so as to promote the development and application of CE with optical fiber LED induced fluorescence.Quantum dot is a new fluorescent probes which develops in recent years. Compared to conventional organic fluorescent dyes, QDs appear to the unique spectral properties, such as wide absorb spectrum and different ones can be exicited by a single light source when different organic fluorescent dyes must be exicited by different wavelength light source. At the same time, QDs is very stable and hard to be blanched. By varying the size of QDs, the emission wavelength can be turned to different color, what make it easy to label, distinction and identification of different biological molecules .So QDs haved been widely used in biochemistry, cell biology, molecule biology etc.and exploring the application in capillary electrophoresis has far-reaching meaning.Here presented is the separation method of several biology active substances, including IgG, epinephrine and dopamine by using a laboratory-built CE system with optical fiber LED induced fluorescence detector. And discussing QDs as fluorescence probe instead of other organic fluorescence dye in capillary electrophoresis. The main contents in the thesis consist of the following three parts:1. An aqueous solution of CdTe QDs was synthesize and conveniently conjugated to glutathione. Based on capillary electrophoretic separation and optical fiber LED induced fluorescence detection, a new method for separation of QDs fluorescence probe and glutathione labeled with QDs was set up, and blue LED was chosen for excitation. The experiment results demonstrate that the QDs-based fluorescent probes may be applied in CE for the determination of biological small molecule.2. The new method for direct determination of IgG was set up by CE with optical fiber LED induced fluorescence detection. A blue LED was chosen for excitation, and FITC was used for precolumn derivatization in capillary zone electrophoresis. Under the optimal condition, a calibration curve ranging from 4.5×10-8 to 1.2×10-6 g/L was shown to be linear. The limit of detection for IgG were 2.0×10-8 g/L. Using this method, the levels of IgG in human serum from healthy donors were determined. The result of detection showed the characteristic with simpleness , rapid separation , high sensitive and without prophase disposal in the system.3. A new analytical method based on capillary electrophoretic separation and optical fiber LED induced fluorescence detection has been developed for the determination of epinephrine and dopamine. Achieved the separation by micellar electrokinetic chromatography in this instrument. The applied voltage, micellar concentration, pH and the concentration of the buffer were optimized. Under the optimal condition, the calibration curve ranging of epinephrine and dopamine from 2.2×10-9 to 1.1×10-7 mol/L and from 2.6×10-8 to 1.2×10-6 mol/L were shown to be linear, respectively. The limit of detection(S/N=3) for epinephrine and dopamine were 2.6×10-8 mol/L, 2.3×10-8 mol/L, respectively. The method was applied to the determination of epinephrine and dopamine in human plasma with satisfactory result. |
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