Detection Of Tumor Markers Based On CdSe Quantum Dots Encoded Hydrogel Microparticles

With the growing of biological technology and modern scientific instruments,people pay more attention to the life sciences,and there are huge demands to screen and detect a large number of biological molecules simultaneously,which makes it particularly important to develop the high-speed and uncomplicated screening methods.Suspension array technique based on microcarriers makes it possible to analyze a variety of targets at the same time in high-throughput mode,wherein the encoded microparticles become one of the important microcarriers.Optical encoded microparticles are the most widely-used encoding microcarriers,but they are still restricted due to signal interference of spectra overlap.In this paper,a preparation system for CdSe quantum dot(QD)-encoded hydrogel microparticles was built based on the microfluidic technique combined with the flow lithography.The encoding number increased owing to the employment of the position encoding,and the encoded microparticles were used to detect tumor markers,carcinoembryonic antigen(CEA)and alpha-fetoprotein(AFP).In the first chapter,the immunoassay methods based on microcarriers,the research of the encoding technology and the preparation methods of encoded microparticles were overviewed.The advantages and limitations of current encoding techniques and conventional synthesis methods of encoded microparticles were summarized in detail.The advantages of the microfluidic technique in the preparation of encoded microparticles were introduced.The purpose and design of this paper were proposed in the end.In the second chapter,the preparation of CdSe QD-encoded hydrogel microparticles was achieved via the multiphase flow lithography technology.The microparticle consisted of two parts,a fluorescence encoding area and a detection area.The former contained quantum dots in different concentration and colors,and the code came from the different colors,intensity and position information.The latter comprised acrylic acid to provide carboxyl for cross-linking with the antigen or antibody.The antibody was successfully cross-linked onto the microparticles,and the content of acrylic acid was optimized.When the content of acrylic acid was 15%of the total volume of reaction solution,more antibodies were coated on the microparticles,and the morphology of microparticles was intact and uniform.The immune response was realized on the surface of the encoded microparticles,and the response of the particles was investigated with different concentrations of the second antibody.Saturated content of the second antibody binded with the first antibody on the surface of microparticles reached 1.5 ?g while the content of the first antibody cross-linked on the microparticles was 4 pg.The sandwich immune response was investigated using the multicolor encoded microparticles to detect CEA,AFP and anti-CEA.The sandwich immune response between CEA and detection antibody could be achieved on the specific encoded microparticles coated with anti-CEA,and the fluorescence detection was completed,and the same to the AFP.In the third chapter,the detection of tumor markers using CdSe QD-encoded hydrogel microparticles were summarized,and their application prospect was discussed.