Fluorescent Nanoparticles

Fluorescent nanoparticles are promising tools for both optical data storage and other technical applications in biochemical, bioanalytical, and medical areas. Current medical and biological fluorescent imaging methods are mainly based on dye markers, which are limited in light emission per molecule, as well as photostability. Nanoparticles overcome these disadvantages offering strong and stable fluorescence. Fluorescent nanoparticles have been successfully used for various types of immunoassays.1,2 In latex agglutination assays some of the limiting factors can be avoided by using very small particles, which reduce the blank absorbance and provides a better colloidal stability.3,4Nanoparticles are also used for more specific purposes like e.g. drug carriers specifically carriers for DNA.5-7

Sigma offers fluorescent nanoparticles based on different materials, each of which provides certain advantages. PAN (Polyacrylnitrile) particles are ideally suited for FRET applications while PD is a novel polymer offering properties similar to polystyrene, but with a much lower oxygen permeability, resulting in a higher photostability for most dyes.

1. Harma, H., Particle-based Bioaffinity Assay Systems - Sensitive Miniature Single-particle Immunoassay, Annales Universitatis Turkuensis, Sarja - Ser. AI Osa - Tom. (2001), p. 273
2. Bangs, L. B., New Developments in Particle-Based Immunoassays: Introduction, Pure and Applied Chemistry 68, No. 10 (1996), p. 1873-1879.
3. Simo, J. M., et. al., Automated Latex Agglutination Immunoassay of Serum Ferritin with a Centrifugal Analyzer, Clinical Chemistry 40, No. 4 (1994), p. 625-629.
4. Medcalf, E. A. et. al., Robust Method for Measureing Low Concentrations if Albumin in Urine, Clinical Chemistry 36, No. 3 (1990), p. 446 - 449.
5. Couvreur, P., Polyalkylcyanoacrylates as colloidal drug carriers, Crit.Rev.Ther.Drug Carrier.Syst., 5, (1988), p. 1-20.
6. Chavany, C., et. al., Polyalkylcyanoacrylate nanoparticles as polymeric carriers for antisense oligonucleotides, Pharm.Res., 9, (1992), p. 441-449.
7. Fattal, E., et. al., Biodegradable polyalkylcyanoacrylate nanoparticles for the delivery of oligonucleotides, Journal of Controlled Release, 53, (1998), p. 137-143.