Preparation Of Water-Soluble Fluorescent Magnetic Nanoparticles For Biological Applications

Magnetic nanoparticle has attracted widespread attentions owing to its unique properties.Magnetic nanoparticle can be water-soluble and florescent by using water-soluble conjugatedpolymer as ligand. The key content of this study is preparation of grafted conjugatedpolymer-stabilized magnetic nanoparticles and their applications in biological. There are threemain parts in the study.1. In the first part of study, anionic water-soluble fluorescent grafted conjugated polymergrafted Fe3O4nanoparticle was prepared. Anionic grafted conjugated polyelectrolyte modifiedFe3O4nanoparticles plays an important role in biological imaging and detection because of itsgood biocompatibility, good water solubility and light stability. The transmission electronmicroscope （TEM）, and dynamic light scattering （DLS） indicates anionic grafted conjugatedpolymer grafted Fe₃O₄nanoparticle showed good water-solubility, uniform hydrodynamicparticle size. Superconducting quantum interference device （SQUID） and confocal imagingshowed that the composite material has very good superparamagnetism and can infiltrate intocell.In addition, MNPs@PFPANa shows large drug loading amout because of its large numbersof electric charge.2. This part: zwitterionic grafted conjugated polymer grafted Fe3O4nanoparticle wassuccessfully prepared by emulsion method. Zwitterionic grafted conjugated polymer graftedFe3O4nanoparticle shows the propertie of anti-protein adsorption and good biocompatibilitybecause of zwitterion on the surface. The test analysis showed that the prepared compositematerial has a very good water solubility, superparamagnetism and fuorescence stability as wellas very low toxicity, and can enter into the cells.These results denominate that this as-preparednanoparticle is a potential tool to use as magneto-optical probe.3. Water-soluble Conjugated Polymer attracts our attention because its amazing performancein self-assembly which due to the rigid main chain and ionic side chain. This part will discuss theself-assembly of anion and cation conjugated polyelectrolyte in different conditions, and avariety of morphology nanobelts was obtained.