标题：Determination of dopamine with improved sensitivity by exploiting an accumulation effect at a nano-gold electrode modified with poly(sulfosalicylic acid)
作者：Li, Juan; Chen, Jia; Zhang, Xiaoli
作者机构：[Li, Juan; Chen, Jia; Zhang, Xiaoli] Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.
通讯作者地址：[Zhang, XL]Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China.
关键词：Polymer film incorporated nano-gold modified electrode;; Electropolymerization; Electrodeposition; Voltammetry; Dopamine;; Preconcentration
摘要：We describe a glassy carbon electrode modified with nano-gold and a film of poly(sulfosalicylic acid) that was obtained by electropolymerization of sulfosalicylic acid. The electrochemical characteristics of the electrode were investigated by using (a) the anionic hexacyanoferrate, and (b) the cationic ruthenium-trisbipyridyl systems as redox probes. The electrode displayed selective and enhanced electroanalytical response towards dopamine (DA), obviously because DA (which is cationic) is accumulated at the electrode, while anions such as ascorbic acid (AA) do not and in fact are being repelled. A 2000-fold molar excess of AA is tolerated after a 120-s accumulation time followed by stripping detection at pH 6.5. Response is linear with the concentration of DA in the range from 0.05 to 5 mu M, and the detection limit is 7 nM (at an S/N of 3) even in the presence of 100 mu M concentrations of AA.