Study on the electrochemical behavior of dopamine with poly(sulfosalicylicacid) modified glassy carbon electrode

A glassy carbon electrode was modified with electropolymerized films of sul fosalicylic acid in pH 5.5 phosphate buffer solution (PBS) by cyclic voltam metry. The modified electrode showed an excellent electrocatalytical effect on the oxidation of dopamine (DA). In PBS of pH 7.4, the oxidation current increased linearly with two concentration intervals of dopamine, one is 5. 5 x 10(-7) to 2.2 x 10(-5) M, the other is 2.2 x 10(-5) to 1.1 x 10(-4) M, with correlation coefficients of 0.9985 and 0.9996, respectively. The detec tion limit obtained by differential pulse voltammetry (DPV) was 5.0 x 10(-9 ) M. The proposed method showed good sensitivity, reproducibility, stabilit y and recovery for the determination of DA. The interference of ascorbic ac id (AA) with the determination of DA could be efficiently eliminated. (C) 2 001 Elsevier Science BN. All rights reserved.