Development of organic dye-doped silica nanoparticles for bioanalysis and biosensors.

The combination of two silica precursors, tetraethylorthosilicate and phenyltriethoxysilane, were utilized to synthesize organic dye-doped silica nanoparticles. The hydrophobic nature of phenyltriethoxysilane keeps the organic dye in the silica matrix, whereas the hydrophilic tetraethylorthosilicate-formed silica allows the resulting nanoparticles to be dispersed in aqueous solutions. Characterization of the nanoparticles showed that they could be synthesized in the nanometer range with high photostability and minimal dye leakage. The silica matrix of the nanoparticles allows different routes of surface biomolecular modification for biosensor and bioanalysis applications. We have shown different applications of the nanoparticles in bioanalysis and in biosensing. Biotin interaction of avidin-coated nanoparticles can be used for the determination of biotinylated bovine serum albumin, and the immobilization of glutamate dehydrogenase on the nanoparticle surfaces enables the nanoparticles to be used as biosensors for glutamate determination.