Preparation Of Polystyrene Fluorescent Microspheres Based On Rare Earth Eu Complex And Application In Biological Labeling

Bioluminescence labeling is a kind of technology which can recognize nucleic acid,protein and other biomolecules by using bioluminescence markers.It has a great application prospect in biology,medicine and agriculture.The preparation and properties of fluorescent labeling materials are the key to the application of this technique.At present,the commonly used fluorescent markers at home and abroad have some shortcomings,such as short fluorescence life,weak fluorescence intensity,easy to be interfered by stray light and background fluorescence,the poor stability,low sensitivity and low resolution of these fluorescence markers have severely restricted the application of the biological fluorescence markers.Therefore,in order to improve the limitation of this technique,it is of great significance to prepare an ideal fluorescent marker.In this paper,two Europium complexes with high luminescent intensity and high luminescent purity were prepared,and polystyrene fluorescent microspheres doped with two Europium complexes were synthesized on the basis of optimizing the preparation process of carboxylated polystyrene microspheres,it has the advantages of good stability,high fluorescence intensity and easy functionalization on the surface of the microspheres.The coupling ability of the prepared microspheres with BSA was studied,and they were successfully applied to the detection of the test strip.The concrete content of this article is the following three parts:1.Two Europium complexes,Eu(DBM)₃phen and Eu(BTFA)(TPPO)₃,were prepared to use dibenzoylmethane(DBM),1,10-phenanthroline(phen),4,4,4-trifluoro-1-phenylbutane-1,3-dione(BTFA)andtriphenylphosphane oxide(TPPO)by solvothermal method.The compositions,structures and properties of the two Europium complexes were characterized by IR,XRD,UV and fluorescence spectra.The results show that Eu(DBM)₃phen and Eu(BTFA)(TPPO)₃ have been successfully prepared.The excitation and emission wavelengths of Eu(DBM)₃phen are 352 nm and 614 nm respectively,and that of Eu(BTFA)(TPPO)₃ are 325 nm and614 nm respectively,all of them have good luminescence intensity and purity.2.Carboxylated polystyrene microspheres were prepared by emulsifier-free emulsion polymerization,and the effects of reaction temperature,type of carboxyl Copolymer monomers and amount of carboxyl copolymer monomers on the size,size distribution uniformity and morphology of the microspheres were investigated,the preparation process of carboxylated polystyrene microspheres was optimized.On this basis,carboxylate polystyrene microspheres doped with Europium Complex were prepared by soap-free emulsion polymerization,the effects of the type of Copolymer,the proportion of Copolymer,the amount of Sodium bicarbonate,the type of carboxyl copolymer and the amount of Europium complex on the size,the uniformity of particle size distribution and the fluorescence properties of the fluorescent microspheres were investigated.The results showed that the optimum preparation conditions were reaction temperature 80°C,distilled water as dispersion medium,initiator KPS 1%,copolymer monomer St and MMA 7:3,and Sodium bicarbonate13%,the content of carboxyl copolymer monomer HEMA-MAH was 10%.Ft-ir results showed that the copolymer was polymerized,and the carboxyl group Copolymer HEMA-MAH was successfully introduced into the surface of the fluorescent microspheres.Tem results showed that the two kinds of fluorescent microspheres had good sphericity,particle size was about 100nm,and monodisperse.The fluorescence spectrum shows that the fluorescence intensity of the microspheres can be controlled by adjusting the amount of Europium complex.3.The surface carboxyl groups of the two fluorescent microspheres were determined,and the coupling ability between the two microspheres and BSA was studied.The results showed that the coupling ability of Eu(DBM)₃phen doped fluorescent microspheres with BSA was 0.124 mg/ml and that of Eu(BTFA)(TPPO)₃doped fluorescent microspheres with BSA was 0.147 mg/ml,a simple test strip capable of detecting HCG was prepared by double anti-sandwich method.