Numerical simulations of non-fluorescent states of carboxyfluoresceins in presence of heavy iodine ions

In the present research, the effects of heavy iodine ions on dark transient state populations of carboxyfluorescein derivatives, each with a different number of bromine atoms attached, were computationally examined via numerical simulations adapted to a widefield fluorescence microscopy integrated with a microfluidics platform. Numerical simulations were carried out by considering geometrical profile of excitation laser beam, microscopy and microfluidics parameters of a proposed experimental design as well as electronic transition rates of fluorescent molecules. Electronic state model of studied dyes was treated as a system of first order ordinary differential equations and time-dependent solutions of long-lived, non-fluorescent dark state populations were computed for each dye at varying potassium-iodine [KI] concentrations. Analytical solutions of state populations were then adapted to a proposed experimental setup to systematically analyze how dark state populations evolve when carboxyfluorescein derivatives pass through excitation beam field in a microfluidics chip under different flow speeds. Computational experiments have successfully uncovered systematic changes in dark triplet and photo-oxidized state populations upon the addition of iodine ions into fluorophore solutions.