Analysis of Fluorescence Decay Kinetics in TwoComponent Systems: a Case Study of Indotricarbocyanine Dyes

Using a two-component system based on indotricarbocyanine dye in low-polarity o-dichlorobenzene as an example, this article examines an approach to analyzing the spectral-kinetic properties of multicomponent systems aimed at determining a physically consistent model for approximating fluorescence decay kinetics. Data analysis was performed using a developed software module that allows one to determine the fluorescence decay duration of one or more centers and set conditions for the search region of the calculation model parameters. The ability to obtain a posteriori distribution of the approximation model parameters is also implemented to determine the range of their possible values. It has been shown that when deconvoluting the fluorescence decay curves of multicomponent systems, achieving the minimum value of χ² (a value less than 1.2) is not a criterion for reliably determining the weighting coefficients and durations of fluorescence decay of the components; it is necessary to use not only mathematically determined calculation conditions, but also to compare the calculated parameters with other photophysical characteristics of each of the components.

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