A new europium chelate of 4,4′′-Bis(4,4,5,5,6,6,6-heptafluoro-1,3-dioxohexyl)-o-terphenyl-4′-sulfonyl chloride -Eu3+-4,7-diphenyl-1,10-phenanthroline-2,9-dicarboxylic acid-3-aminopropyltrimethoxysilane (BHHCT-Eu3+-DPPDA-APTMS) doped core-shell Ag@SiO2 nanocomposite was synthesized successfully by a facile water-in-oil microemulsion method. The morphology, crystalline phase, composition and optical properties of the nanocomposite were investigated with examining of various influence facts on the fluorescent intensity of the nanocomposite. After optimizing the reaction conditions, an optimal metal-enhanced fluorescence (5.0 fold) was achieved and the desired novel nanocomposite was obtained. The bioimaging application of the prepared nanocomposite shows that bright upconversion luminescence can be observed when nanocomposite-labeled HeLa cells are excited with 980nm light. It is expectable that the as-prepared nanocomposite is a potential fluorescent nanoprobe that can be applied in high sensitive bioimaging.