Preparation And Properties Of Carbon Nanotube-based Magnetic And Fluorescencent Nanomaterials

With the rapid development of science and technology, a variety of new functional nanomaterials emerges one after another which constantly provides new methods for basic research and practical applications. Because of the requirements for miniaturization,high precision and high sensitivity, people show great concern of the multi-functional nano-materials.Based on the unique properties of quantum dots (QDs) and magnetic nanoparticls (MNPs), they often play important roles in the field of multi-functional nanomaterials, with the biomedical research especially. Materials which show targeting and two-signal response increase the sensitivity of various detection methods, such functions which are of important theoretical significance and application value. So, in this dissertation, we described detailedly the synthesis of Fe3O4 magnetic nanoparticles (Fe3O4MNPs) in a copolymerization way, the assembling of surface modified Fe3O4MNPs by using coupling agent and water-soluble core/shell QDs, the structure and properties of the assembled magnetic fluorescent materials, here are the conclusions:1. The highly structured Fe3O4MNPs with excellent purity can be synthesized on functionalized multi-walled carbon nanotubes by co-precipitation technique (Fe3O4/OMWCNTs). These nanoparticles can be uniformly dispersed on carbon nanotubes which overcomes the agglomeration phenomenon in the traditional co-precipitation method. Fe3O4/OMWCNTs were attached with -NH2 groups via covalently grafted with y-aminopropyltriethoxysilane. Under the action of an external magnetic, the Fe3O4-NH2/OMWCNTs material displays a strong magnetic response.2. The Cadmium Selenium (CdSe) QDs were prepared by injecting TBP-Se precursor into Cd-SA stock solutions at high temperature. Based on CdSe QDs, two kinds of oil-soluble core/shell CdSe/ZnS, CdSe/CdS/ZnS were synthesized. The oil-soluble QDs were functionalized with 3-mercaptopropionic acid (MPA), degraded gelatin, respectively. Through these processes, water-soluble QDs with different function groups were prepared. The modificated core/shell QDs show good dispersion properties, chemical stability and high fluorescence quantum yield in water.3. Amino coupled Fe3O4/OMWCNTs and MPA-coated QDs or gelatin-coated QDs are assembled through molecular coupling technology. Under the action of an external magnetic, the assembled multifunctional material displays a strong magnetic response. In the fluorescence microscope, this multifunctional material has a strong fluorescent property which shows a broad application prospect in the fluorescent labeling and biological imaging.