In an effort to prepare efficient and uniform biolabels

we have developed a novel fluorophore doped silica nanoparticles via water-in-oil(W/O)microemulsion method.The controlled hydrolysis of tetraethyl orthosilicate(TEOS)in W/O microemulsion leads to the formation of monodisperse fluorophore doped silica nanoparticles.By synthesizing of monomer dansyl-Cl(DNS-Cl)silica precursor

we have successfully prepared fluorescent hybrid silica nanoparticles of DNS-Cl.The fluorophores are well protected from the environment when they were doped inside the silica network.The transmission electron microscope(TEM)photograph showed that the particles are very uniform

they are spherical and monodispersed with a diameter of about 40 nm.The excitation maximum and emission maximum

compared with the monomer precursor

have a blue-shift.The fluorescence intensity of the fluorophore doped silica nanoparticles passed through a maximum with increasing monomer precursor concentration

the optimal loading is 100 μL of monomer precursor.The effect of pH on monomer precursor is very distinct

both the fluorescence intensity and the excitation wavelength have changed a lot

but the fluorophore doped silica nanoparticles are nearly insusceptible

which indicates that core-shell structure reduces the effect of the environment on fluorophores.The method significantly reduces fluorescent dye leaching from the nanoparticles too

since there is a firm chemical bond between DNS-Cl and APTEOS

the particles are potential of good biocompatibility

since they have a pure silica surface and can thus be modified easily with many biomolecules for added biochemical functionality.The particles can be accepted as an effective biological labels.