Dongguang Yin

Preparation of A Novel Type of Fluorescein Isothiocyanate-Doped Fluorescent Silica Nanoparticle and Its Application as pH Probe

Abstract In this study, a novel type of core-shell fluorescein isothiocyanate (FITC)-doped fluorescent silica nanoparticle was synthesized and used as an intracellular pH sensor. First, a silane reagent of 3-aminopropyl-trimethoxysilane (APTMS) was used to synthesize a novel precursor FITC-APTMS. Then, FITC-APTMS/SiO2 (FAS) nanoparticles were obtained using water-in-oil (W/O) microemulsion technique in the presence of tetraethoxysilane (TEOS). Characterizations by transmission electron microscopy (TEM) and fluorescence spectroscopy show that the nanoparticles are spherical, monodisperse, and uniform in size with the diameters being (150 ± 15) nm. They are also highly fluorescent and highly photostable. When the nanoparticles were dispersed in aqueous solution under ultrasonic treatment for 6 h, no obvious dye leaking was observed. It was found that the fluorescence of the nanoparticles was pH sensitive, and the pH response range was 3.6–9.7, with a linear range of pH 6.0–9.0. The FAS nanoparticles could be phagocytosed by murine neural stem cell and thus could be applied to detect intracellular pH value of single cell.

Preparation, Characterization and Fluorescent Immunoassay Application of Rubpy-Doped Silica Nanoparticles

A novel type of Rubpy-doped fluorescent nano-particles has been prepared using a water-in-oil(W/O) microemulsion method[1]. Characterizations by transmission electron microscopy, fluorescent spectra, photostability experiments and dyeleaking experiments show that the nanoparticles are spherical, monodisperse, and uniform in sharp and size (70±±5nm). Due to a lot of fluorescent dye molecules encapsulated in the silica matrix that also severs to protect Rubpy dye from photodamaging oxidation, the nanoparticles are extremely bright, photostable and chemical stable. The prepared nanoparticles have been used as fluorescent probe successfully in fluorescent immunoassay.

Preparation of luminescent dye doped core-shell nanoparticles and their application in cell recognition

Based on the reverse microemulsion technique, luminescent dye doped core-shell nanoparticles have been prepared by employing silica as the shell and Rubpy as the core of the nanoparticles, which have an excellent solubility and dispersibility, especially amine groups have been modified on their surface synchronously. In comparison with Rubpy, these nanoparticles show superiority in chemical and photo-chemical stability. The Rubpy doped core-shell nanoparticles successfully recognize neural stem cells.

Preparation and characterization of a novel silica fluorescent nanoparticles with DPPDA-Eu 3+ doped

A new ligand of 4,7-Diphenyl-1,10-phenanthroline-2,9-dicarboxylic acid (DPPDA) and Eu3+chelate compound of this ligand were prepared. Then DPPDA-Eu3+ doped silica fluorescent nanoparticles of DPPDA-Eu3+/SiO2 with primary amino groups on their surface were developed using a water-in-oil (W/O) microemulsion technique. Characterizations by transmission electron microscopy, fluorescent spectra, fluorescent molecules leaking experiments and photostable experiments show that the nanoparticles are spherical and uniform in size of 80±8nm, monodisperse, highly fluorescent signal and highly photostability. No obvious of fluorescent molecules leaking was observed. The nanoparticle as a novel fluorescent probe is expected to be applied in highly sensitive bioassays such as time-resolved fluorescence, biosensor and biochip.