Abstract: A new electrochem. sensor for the highly sensitive and selective determination of dopamine was developed, based on the use of a glassy carbon electrode modified with cobalt(II) polymer.Both electrochem. and morphol. characterizations were investigated.Square wave voltammetry (SWV) was used for the determination of dopamine.From the SWV results obtained on the modified electrode under the optimized conditions, the successive addition of dopamine increased the anodic peak current.The results obtained show a linear response of the electrode modified with Co(II) polymer in a wide concentration range.Each concentration decade is characterized by a new calibration plot with a corresponding math. expression.The highest sensitivity (13.182) was obtained for the lowest concentration range, and the detection limit of 0.03 μM, calculated based on the 3 x sb/m criterion, indicates a very high sensitivity and great application potential.When analyzing a real sample, the modified electrode showed good electroanal. activities in terms of oxidation of dopamine, good anti-interference ability, stability, reproducibility, and potential applicability in com. pharmaceutical samples.