Synthesis And Characterization Of New Fluorescent Nanoparticles And Its Application In Immunoassay

As a member of multitudinous fluorescent labels, dye-doped nanoparticles have widespread prospects of application in the biology and medicine domain because of its excellent characters such as the strong fluorescence intensity, easy surface modification, low toxicity and easy preparation. However, the dye leakage from the matrix is still a problem no matter which kind of matrix was used. In order to solve this problem, lots of methods have been employed in the issued papers. Conjugation of the dye with the precursor of nanoparticles matrix, transforming the solubility of dye, creating the electrostatic attraction between of FNPs matrix and dye, increasing the size of dye, and so on, are the usually used methods. To a certain extent, these methods could decrease the leaking of the dye from the NPs matrix, but most of the methods have their intrinsic disadvantages. For example, it is very difficult to conjugate the dye without active group with the precursor of nanoparticles matrix. In this study, a new type of fluorescent nanoparticles (FNPs) has been developed with precipitation polymerization.Chapter One We have reviewed nanoparticles and its application in immunoassay. The research section contains three subunits.Chapter Two A novel kind of fluorescent nanoparticles (FNPs) has been prepared using a precipitation polymerization method. Methacrylic acid, trimethylolpropane trimethacrylate and azobisisobutyronitrile were used as functional-monomer, cross-linker and initiator, respectively. Compared with other fluorescent nanoparticles, the FNPs have the characteristics including low dye leakage and good photostability.Chapter Three In this chapter, we have developed a detection method of IL-4. The imprinted fluorescent nanoparticles were labeled on anti-IL-4 monoclonal antibody. IL-4 was measured based on the specific interaction between captured IL-4 antigen and fluorescent nanoparticles-labeled anti-IL-4 monoclonal antibody. The detection limits were 0.3ng/mL.The RSD for eleven parallel measurements of 2.0 ng/mL IL-4 was 3.2%. The results demonstrate that the method offers potential advantages of sensitivity, easily labeling to the antibody, optical detection.Chapter Four A novel method of detectingα-fetoprotein was developed. The method combined the model of Ab-Ag-Ab-Ab* with fluorescence microscopy imaging. The software, Image-pro plus 6.0, was used to gain the data of image. The detection limits were 0.3ng/mL. The results demonstrate that the method offers potential advantages of easily labeling to the antibody, sensitivity, simplicity and reproducibility for the determination of AFP. And the method is applicable to the determination of AFP in serum samples.