Determination of dopamine using the fluorescence quenching of 2, 3-diaminophenazine

A facile and sensitive fluorescent strategy for the determination of dopamine is reported using 2, 3-diaminophenazine. Dopamine caused autooxidation in the presence of oxygen with catalysis by Mn2+ and formed 2, 3-dihydro-1H-indole-5,6-dione. 2, 3-Diaminophenazine provided relatively strong fluorescence. 2, 3-Diaminophenazine in aqueous solution caused fluorescence quenching when the aminochrome condensed with 2, 3-diaminophenazine to allow the determination of dopamine. Under the optimized conditions, the linear dynamic range for dopamine was from 2.0 × 10−6 mol · L−1 to 6.1 × 10−5 mol · L−1 with a detection limit of 1.76 × 10−6 mol · L−1.