This article investigates the influence of the electrostatic potential of a charged polyion on the kinetics of a binary reaction of molecular ions in a polyelectrolyte solution. As a model system, an aqueous salt solution of DNA with a luminescent bimolecular probe consisting of a cationic (Rhodamine 6G) and an anionic (Erythrosin) organic dye was considered. DNA, as a highly charged polyion, promotes the adsorption of the cationic dye, while the anionic dye remains in the solution, enabling long-range energy transfer between the donor (Rhodamine 6G) and the acceptor (Erythrosin). The effect of adding a monovalent salt (NaCl) on the fluorescence spectra of the solutions was experimentally studied, confirming changes in the system’s structure due to the neutralization of the DNA charge by Na+ ions. A mathematical model was developed based on the Poisson-Boltzmann equation and the Smoluchowski equation, taking into account electrostatic interactions in the system. The results of numerical modeling demonstrate the importance of considering the electrostatic potential for an accurate description of reaction kinetics in polyelectrolyte solutions. Neglecting these interactions can lead to significant errors in theoretical analysis. #CSOC1120.