A method of determining donor–acceptor distribution functions in Förster resonance energy transfer

We describe a method of determining the distribution function associated with acceptors partaking in Förster resonance energy transfer (FRET) from excited donors. Unlike previous approaches to this problem the method described makes no a priori assumption about the nature of the distribution. The use of an acceptor distribution function in analyte sensing is demonstrated for the first time. In the case of glucose sensing via FRET from Concanavalin A labelled with allophycocyanin to malachite green labelled dextran, the change in the acceptor distribution is shown to be a more sensitive sensing parameter than either the mean fluorescence lifetime or Förster γ value.