The Synthesis Of Nanoparticle And Their Applications In Cell Image And Determination Of Vitamin C

Nanoparticles have been widely used in chemical and biological sensing, cell imaging owing to their unique plasmon resonance properties and fluorescent properties. Fabricating and preparing stable, water soluble and biocompatible nanoparticles is the foundation for their applications. In this thesis, several silica nanoparticles such as dye-doped silica nanoparticles, core-shell silica nanoparticles were facilely synthesized. We investigated the potential applications of such nanoparticles in cell imaging and vitamin C detection. The main contents are as follows:1. Luminescent silica nanoparticles (NPs) doped with ruthenium complexes were synthesized using a reverse microemulsion method. These NPs had various advantages including strong fluorescence emission, low toxicity and easily surface modification. They could be specifically applied in the cellular prion protein (PrPC) labeling and imaging in human bone marrow neuroblastoma cells (SK-N-SH cells) after modification with anti-PrPC aptamer, wherein NPs were employed as labeling reagents and aptamers as biomolecule-specific recognition agents.2. Multicolor silica nanparticles were prepared by incorporating two dyes into the silica matrix using reverse microemulsion and coprecipitation methods. Recognition elements, such as aptamer, could be attached to the surface of nanoparticles covalently, which could bind to target specificitily. It was anticipated that these aptamer-modified nanoparticles could be employed in the territory of cell imaging..3. Core-shell silica nanospheres using silver nanocubes as the core and silica as the shell had been successfully fabricated. At the same time, the orgnic dye FITC could also be doped in the silica nanosphere, which exhibited fluorescent signal and scattering signal simultaneously. They could be observed under the confocal microscopy and dark field microscope respectively. These nanoparticles had good cell compatibility and could be served as a good probe for cell imaging.4. A fast, simple and reliable method for the detection of vitamin C by employing gold nonorods as the sensing platform is proposed on the basis of the shift of localized surface plasmon resonance (LSPR) absorption of gold nanorods resulting from the formation of Au@Ag core/shell nanorods. Under optimum conditions, LSPR gets shifts with the increase of vitamin C in the range of0.25-10.0μmol/L and the limit of detection (3σ) is0.12μmol/L.The developed method is successfully applied to the determination of vitamin C in troches with the recovery of95.4%-106.0%, identical with the results measured with China Pharmacopeia.