Research Of The Effect To The Performance Of Magnetic Fluorescent Nanomaterials With Different Surface Modifiers

With the rapid development of nanotechnology, a single nanoparticle can not meet the complex demands in practical applications, both material and fluorescent-labeled magnetic separation function become a hot topic, so that the material can be widely used in environmental monitoring, cell separation, markers, etc. The presence of magnetic energy can be a good material for recycling, not only reduces costs, but also to achieve the environmentally friendly action. Now how the magnetic nanoparticles and quantum dots complex is the focus of research, but also to improve the biocompatibility of magnetic fluorescent nanoparticles, reducing the particle size, to retain high magnetic response and fluorescence visualization performance. On the surface of the magnetic nanoparticles and quantum dots modifications can effectively solve these problems, so the study of the surface modifier selection is very important. Modification of the quantum dot material is usually selected with amino, carboxyl or thiol, pertaining to magnetic nanomaterials divided into three categories:?1? inorganic nanomaterials;?2? small organic molecules;?3? organic macromolecules. Fully visible, which is a valuable research and application prospects, the paper therefore carried out the following research areas:?1? Preparation of Quantum Dot CdSe/CdS. In oleic acid and liquid paraffin solvents to CdO, Se and S for raw materials oil phase core-shell CdSe/CdS, with thioglycolic acid on the surface of the quantum dot can be modified to have a hydrophilic and surface-rich carboxy, to facilitate the next application. The results show that the quantum dot has a strong fluorescence, particle size uniform and well dispersed.?2?The use of small organic molecules, citric acid?CA? on Fe₃O₄ magnetic nanoparticles modified. By chemical coprecipitation magnetic nanoparticles, and then citric acid on Fe₃O₄ nanoparticles was modified to give Fe₃O₄/CA nanocomposite particle surface rich in carboxyl groups, containing a large amount of negative charge. In the role of the federation ethylenediamine, Fe₃O₄/CA nanoparticles and CdSe/CdS success together.After various types of characterization, the results show: Fe₃O₄/CA@CdSe/CdS fluorescence composite magnetic particles have a strong magnetic response and excellent fluorescence characteristics, can be stable, suitable for application.?3? The use of organic macromolecules, mannan oligosaccharides?MOS? for Fe₃O₄ magnetic nanoparticles modified. Chemical coprecipitation magnetic nanoparticles Fe₃O₄,then mannooligosaccharide magnetic particles wrapped synthetic surface hydroxylated Fe₃O₄/MOS, after adsorption and cooperation with key connected with the modifiedquantum dots, obtained success Fe₃O₄/MOS@CdSe/CdS magnetic fluorescent bifunctional material. Its characterization, the results show: The Magnetic Fluorescent Bifunctional nanoparticles have good magnetic response, fluorescence performance is still very good,can be stable for easy application.?4? The use of inorganic nanomaterials Nano Au pair Fe₃O₄ magnetic nanoparticles modified. As a direct Fe₃O₄ magnetic nanoparticles modified gold nanoparticles are not well used directly in terms of bio-medicine, the use of gold nanoparticles can be a good composite containing amine compound, so the first?PEI? modified with polyethyleneimine Fe₃O₄, and in situ reduction of composite Au nanoparticles. After re-connecting with the modified quantum dots, obtained Fe₃O₄/PEI/Au@CdSe/CdS composite particles,characterization, results show that: the composite material has a good magnetic response and a good fluorescent properties, as well as Au nano characteristics in the field of the environment has a very important application prospects.This is the first systematic study of the three different types of modifiers, and four types of quantum dots modifiers, by contrast response modifier effect on the magnetic properties of magnetic and fluorescent properties of fluorescent nanoparticles to guide in practical applications, we can choose the right according to the needs of different magnetic and fluorescent modifiers.