Selective determination of dopamine in presence of ascorbic acid and uric acid at hydroxy double salt/surfactant film modified carbon paste electrode

A sensitive and selective electrochemical method using a hydroxy double salt/surfactant film modified carbon paste electrode (HDS/SDS/CPE) was developed for the electrochemical determination of dopamine. The HDS/SDS/CPE shows an excellent electrocatalytic activity towards the oxidation of dopamine in 0.1 M phosphate buffer solution (pH 7.4) and the detection limit of DA was 1 × 10−7 M. The interference studies showed that the modified electrode exhibits an excellent selectivity towards dopamine (DA) in the presence of large excess of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for DA–AA and DA–UA were about 187.8 mV and 110.7 mV respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. This work provides a simple and easy approach to selectively detect the dopamine in the presence of ascorbic acid and uric acid in physiological samples.