Multiplexed Diagnostics And Spectroscopic Ruler Applications With Terbium To Quantum Dots Fret

In this contribution we present the application of five different commercially available semiconductor core/shell quantum dots (Qdot (R) Nanocrystals - Invitrogen Corp.) as multiplexing FRET acceptors together with a commercial supramolecular terbium complex (Lumi4 (R)-Tb - Lumiphore Inc.) as donor in a homogeneous immunoassay format. To realize the molecular recognition necessary for a FRET assay, the terbium complex was labeled to streptavidin (sAv-Lumi4-Tb) and the QDs were surface functionalized with biotin (Biot-QD). The biotin-streptavidin binding serves as a proof-of-principle representative for many biological interactions taking place on the nanometer scale (e. g. immunoassays). The presented FRET system can be efficiently used for the detection of inter-and intramolecular processes for clinical diagnostics and biomedical spectroscopy as well as molecular ruler applications and microscopy.