Selective Detection of Dopamine in the Presence of Ascorbic Acid at Poly (m-Aminobenzene Sulfonic Acid)

摘要

Poly (m-aminobenzene sulfonic acid, m-ABSA) films were electrochemically prepared by cyclic voltammetry (CV) in 0.1 mol L–1 KCl solution. The dopamine (DA) selectivity of polymeric electrodes prepared at the different thicknesses was examined in the presence of ascorbic acid (AA). The results showed that the modified electrode showed an excellent electrocatalytical effect towards oxidation of dopamine (DA) and ascorbic acid (AA). Electrostatic interaction between the negatively charged poly(m-ABSA) film and either cationic DA species or anionic AA species favorably contributed to the redox response of DA and AA. Moreover, the regular and repetitive responses for dopamine were obtained even in the presence of the some interfering substances such as ascorbic acid, NaCl, NaClO4, Na2SO4 ,NaNO3 and KCl.