Switchable luminescent probes using resonance energy transfer

Understanding the molecular basics of recognition events in chemistry is crucial for a wide range of disciplines. Luminescence spectroscopy is an appealing way of obtaining information on molecular-scale recognition events, as sensitive, realtime detection and subnanometer spatial resolution can be achieved. Measurements in biological media are generally difficult because of the interference from the sample and the non-zero background. Resonance energy transfer (RET) between a luminescent donor and acceptor (D-A) is possible when excitation of the D is followed by energy transfer to A, that emits at increased wavelengths. Molecules that undergo RET triggered by the presence of a target molecule would allow a specific signal to be identified, as emission would occur only in the presence of the species of interest. Due to the increased emission wavelengths, interference with sample autofluorescence is avoided. The synthesis of donor-acceptor-quencher (D-A-Q) triads, equipped with coumarin donors, nucleoside quenchers, and organic or lanthanide acceptors, that are able to undergo triggered RET will be presented