Taking into account the conformational dynamics of macromolecules when analyzing luminescent probe signals

A mathematical model is proposed that takes into account the specific features of electronic excitation energy transfer between the molecular probes sorbed on a polymeric chain in a liquid solution. The kinetics of the process is described from the standpoint of the stochastic changes in macromolecular conformations. The results of numerical solution of the problem are described, as well as the analytical expressions obtained in the context of perturbation theory for a low transfer rate and/or fast conformational dynamics of the macrochain. A channel of nonlinear (with respect to excitation) deactivation resulting from binary annihilation of closely spaced excited centers is considered. Expressions for the efficient rate of mutual quenching and delayed annihilation fluorescence of the probe are obtained. The time dependences of characteristic luminescent signals and the parametric curves of relative fluorescence quantum yield are given.