Abstract: Cy3 dye doped core-shell silica fluorescent nanoparticles was synthesized by using of water-in-oil microemulsion technique, with biomolecules modified Cy3 as the core and the silica produced from the hydrolysis TEOS(tetraethyl orthosilicate) as the shell. In this paper, five kinds of bimolecules with different pI values for preparation of Cy3 doped core-shell silica fluorescent nanoparticles were investigated. The results show that very bright and photostable Cy3 doped core-shell silica fluorescent nanoparticles can be both prepared by using Cy3-IgG or Cy3-polysine modified as the core material. And then Cy3-IgG was selected as a demonstration to prepare Cy3 doped core-shell silica fluorescent nanoparticles. A novel fluorescence marker was based by using the Cy3 doped core-shell silica fluorescent nanoparticles. The flu virus DNA was detected by using the Cy3 doped core-shell silica fluorescent nanoparticles, and the detection limit of the target DNA is 3.51×10^-10 mol/L.

Key words: Cy3 dye, Water-in-oil microemulsion, Core-shell fluorescent nanoparticals, DNA detection