Long-wavelength long-lifetime luminophores

We describe a new approach to making luminophores that display long emissio n wavelengths, long decay times, and high quantum yields. These luminophore s are covalently linked pairs with a long-lifetime resonance-energy-transfe r (RET) donor and a long-wavelength acceptor. The donor was a ruthenium (Ru ) metal-ligand complex. The acceptor was the Texas Red. The donor and accep tor were covalently linked by polyproline spacers. The long-lifetime donor results in a long-lived component in the acceptor decay, which is due to RE T. Importantly, the quantum yield of the luminophores approaches that of th e higher quantum yield acceptor, rather than the lower quantum yield typica l of metal-ligand complexes. The emission maxima and decay time of such tan dem luminophores can be readily adjusted by selection of the donor, accepto r, and distance between them. Luminophores, with these useful spectral prop erties can also be donor-acceptor pairs brought into close proximity by som e biochemical association reaction. Luminophores with long-wavelength emiss ion and long lifetimes can have numerous applications in biophysics, clinic al diagnostics, DNA analysis, and drug discovery.