A luminescent method for determining glycine based on competitive complexation of Cu2+ ions with ciprofl oxacin and an amino acid is proposed. Formation of a Cu2+ complex with a fl uoroquinolone derivative is shown using spectrophotometry. The resulting complex does not have fl uorescent properties, unlike the ligand itself. In the presence of additives of complexing agent ions in a ciprofl oxacin solution, its fl uorescence is quenched.
