Numerical experiments of fluorescence quenching studied by the Smoluchowski-Collins-Kimball model

The paper reports on the recovery of the Smoluchowski-Collins-Kimball (SCK) parameters from simulated fluorescence quenching decays for a donor of a subnanosecond lifetime. The accuracies are established to which the reaction distance (R), the sum of diffusion coefficients of donor and quencher (D) and the specific rate constant of the quenching process (κ) can be recovered. It has been shown that taking into regard the character of the correlation between κ and R, the determination of κ is possible to a much higher accuracy than hitherto achieved. As it is impossible to determine correctly the SCK parameters on the basis of a single fluorescence decay, a minimum number of experiments needed to get a good agreement between the recovered SCK parameters and the values of these parameters used in the simulations has been specified. Our results indicate that not only the full width at half maximum of the instrument response function (IRF) but also the shape of the rising slope of IRF have important effect on the accuracy of the recovered R, D, κ parameters.