Red Carboxyl Fluorescent Nanoparticles are europium chelated carboxylate fluorescent microspheres that are monodispersed and have a broad Stokes Shift and a very long lifetime (milliseconds). The extended lifetime enables the europium chelate beads to be used in a wide range of time resolved fluorescence applications including lateral flow assays, and immune/histological research.
Use of the europium beads lowers by several fold the detection limit of an assay from that achieved with a conventional fluorophore, as the europium beads have higher fluorescence intensity and eliminate background interference from relatively short-lived matrix fluorescence.