Determination of dopamine in the presence of ascorbic acid by poly(styrene sulfonic acid) sodium salt/single-wall carbon nanotube film modified glassy carbon electrode.

In this study, poly(styrene sulfonic acid) sodium salt/single-wall carbon nanotube film was cast onto the surface of glassy carbon electrode and the electrochemical behavior of the modified electrode was investigated. The results show that the anodic peak current is proportional to the concentration of dopamine in the range of 1.6 x 10(-8)-6 x 10(-4) M. The detection limit is 8 x 10(-9) M. The interference of ascorbic acid with the determination of dopamine could be eliminated due to the very distinct attracting interaction between dopamine cations and the negative poly(styrene sulfonic acid) sodium salt film in pH 7.0 phosphate-buffered saline solutions. The proposed method exhibits good sensitivity, selectivity, and reproducibility.