Development of a time-resolved fluorometric detection system using diffusion-enhanced energy transfer

A novel detection system using both emission energy transfer and time-resol ved fluorometry (TRF) was developed, with a europium chelate as the energy donor and a novel fluorophore SNR1, excitable with long-wavelength light co rresponding to europium emission, as the energy acceptor. When the donor an d acceptor molecules were mixed in solution, energy transfer was observed w ithout direct attachment of the donor and the acceptor, via a diffusion-enh anced energy-transfer mechanism. Thus, the acceptor emission can be detecte d as a long-lifetime fluorescence in TRF. When the fluorescence properties of the acceptor molecule are changed by interaction with an enzyme or other bioactive molecule, the change can be detected as a long-lived sensitized emission. If we develop or select suitable acceptor molecules, this simple and convenient system should be applicable to a nide variety of bioactive m olecules. Since it is based on TRF, it can be used for high-resolution assa y.