Life Sciences, Inc. - Dye Doped Silica Nanoparticles

Life Sciences has developed a technology to produce dye-doped silica nanoparticles (DDSNP) that have significant advantages over organic fluorophores and quantum dots. These nanoparticles can be produced in sizes ranging from 20 to 100 nm diameter with a narrow size distribution. Particles encapsulating thousands of dye molecules are extremely bright, providing high signal amplification. The silica matrix is an excellent substrate for surface modification and biomolecule immobilization.

Particle sizes are generally measured by transmission electron microscopy (TEM), scanning electron microscopy (SEM), or dynamic light scattering. As shown in figures below, DDSNP are usually found to be spherical.

Dye-doped silica nanoparticles demonstrate similar absorption and emission spectra compared to native dye molecules, although the optimal excitation and emission wavelengths of the particles may be slightly shifted from those of the pure dye molecules.

Each dye-doped silica nanoparticle contains a large number of luminescent dye molecules, so that the DDSNP can produce a strong emission signal when it is properly excited. Signal enhancement from two to five magnitudes that of a conventional dye is the foundation for DDSNP utility in bioimaging and ultrasensitive bioanalysis.

Chemical binding, or covalent coupling, can permanently conjugate biomolecules on DDSNP. The particles are first surface functionalized with thiol (-SH), cyanate ester (-OCN), amino (-NH2) or carboxyl (-COOH) group. Further surface modification can immobilize biotin, DNA, antibodies, enzymes, and other proteins on the nanoparticles.

Amine-Modified DDSNP

Customized to fit your application

LSI can provide simple and complex customization, including particle size, fluorescent marker, Stokes Shift and surface activation. Förster Resonance Energy Transfer (FRET) allows us to create dye systems with a flexibility of excitation and emission wavelengths not available in single-fluor systems. It is even possible to have multiple emission peaks from a single excitation wavelength.

The following links lead to standardized products with the indicated fluorescent label, or click ‘custom’ to submit your specifications for a custom nanoparticle. Please contact us for detailed information.

FLUORESCEIN	HEX	TAMRA
ROX	RUBPY	NANOPARTICLE HOME

References:

G Yao et al, FloDots: Luminescent Nanoparticles Anal Bioanal Chem, 2006, 385, 518-524
W Lian et al, Ultrasensitive Detection of Biomolecules with Fluorescent Dye-Doped Nanoparticles, Anal Biochem, 2004, 334, 135-144.
X Zhao et al, A Rapid Bioassay for Single Bacterial Cell Quantitation Using Bioconjugated Nanoparticles, PNAS, 2004, 101, 15027-15032.