Abstract: The fluorescence-doped silica nanoparticles (FDS-NP) were synthesized in a microemulsion system of polyoxyethylene nonylphenyl ether (OP-10)/ cyclohexane/ammonium hydroxide. To elucidate the character of FDS-NP, techniques of electron microscopy, analysis of spectrum and collisional quenching of fluorescence were used. In order to study the fluorescent signal and intensity of FDS-NP in the cultured cells, laser-scanning confocal microscope and the analysis of flow cytometry were utilized. The results showed that the size of FDS-NP was very small (about 20 nm), the distribution was narrow, the shape was circular and lubricity, and the fluorescence was photostable. Cultured cells could efficiently uptake FDS-NP, and yield high fluorescent signal and intensity. All these indicated that FDS-NP is an important nanoparticulate biomarker, and is applicable to many areas of modern biochemical analysis, such as ultrasensitive detection, immunoassys, as well as cellular biology.

Key words: Nanoparticulate biomarker, Silica nanoparticles, Rhodamine B