Synthesis, photoluminescence and bioconjugation of rare-earth (Eu) complexes-embedded silica nanoparticles

Eu(DBM)3Phen-embedded silica nanoparticles were synthesized in water-in-oil (W/O) microemulsion containing aqueous phase of Eu(DBM)3Phen, surfactant Triton X-100, cosurfactant octanol and oil-phase cyclohexane. The size and morphology of the nanoparticles were characterized by transmission electron microscopy (TEM). The low-temperature time-resolved emission spectra indicate that the Eu complex in the silica nanoparticles have longer lifetime than that of the pure complex. Under 355 nm continuous excitation, the nanoparticles show high resistance to photobleaching. The free amino groups were attached to silica surfaces by copolymerization of 3-aminopropyl(triethoxy)silane. Preliminary results demonstrated that the silica-coated Eu complex nanoparticles can be a probe in the detection of biomolecular interactions.