Sensitized room-temperature luminescence in reverse micelles using lanthanide counterions as acceptors

The analytical usefulness of sensitized room-temperature luminescence in reverse micelles using lanthanide counterions is examined. The technique is based on the unique luminescent properties of tripositive lanthanide metal ions as counterions for the surfactant and the molecular organization produced by reverse micelles. After excitation, the analyte molecule transfers its triplet-state energy to an acceptor molecule (lanthanide), which subsequently emits luminescence. Two surfactants with different lanthanide counterions have been synthesized and characterized by spectroscopic and mass spectrometric techniques. When compared to the lanthanide salt, the sensitized luminescence of the lanthanide surfactant is substantially enhanced. The exact locations of the analyte and the counterion in the micellar system are discussed. The efficiencies of energy transfer for the two surfactants are compared.