Preparation Of Water-soluble Quantum Dots And Magnetic Nanoparticles

Functional nanomaterials which came into the world with the birth of nanoscience and nanotechnology have been widely applied in the intersection of nanotechnology and biotechnology for their extraordinary properties. Especially for those nanomaterials which can be used for biolabeling, bioimaging, separation in the nanobiomedical research, such as Quantum Dots and magnetic nanoparticles.Because of its small radius, strong coercive force, superparamagnetism, excellent dirigibility, magnetic nanoparticles have been successfully used in the diagnosis and treatment o,f disease, separation of biosubstances.But those magnetic nanoparticles prepared by traditional ways all have limitations such as inhomogeneous radius, easy to aggregate in some degree. Quantum Dots are superior to traditional organic fluorescent dyes for their exceptional fluorescence characteristics, and have been extensively used in the preparation of fluorescent probes, biolabeling and bioimaging.However, all kinds of present ways of modifying Quantum Dots have some defects such as unstable, complex procedures,nonspecific modification. At the same time, how to integrate magnetic and fluorescent nanoparticles to construct bifunctional or even multifunctional nanodevices is an attractive question in the regime of nanomaterials.This thesis report works as follows: 1) High quality iron-oxide nanoparticle was prepared from simple inorganic salt, result of TEM, XRD shows that the product is in good crystal structure, monodispersed, uniform in radius, size controllable, with excellent magnetic dirigibility.This method is cheap, with low toxicity, safe, repeatable and convenient to produce, which made it possible to prepare in large batch in lab. 2) Made use of the hydrophobic cavity of cyclodextrin to successfully transfer the Quantum Dots into water phase.Compared with other means, this method is easy to handle, low in price, with good repeatability, and the product is with excellent water-solubility and stability. And by this means, it's hopeful to conjugate with biomolecules specificly and have wide use in monitoring of hazards to environment. 3) Prepare silica nanosphere by sol-gel andmicroemulsion methods, and incorporate Quantum Dots and magnetic nanoparticles into the silica to get new type magnetic fluorescent bifunctional nanomaterial.