多巴胺聚合物膜电化学检测多巴胺.pdfVIP

1578 Full Paper Electrochemically Degraded Dopamine Film for the Determination of Dopamine Hye-Young Chang,a Dong Il Kim,b Yu Chul Park*b a Institute of Basic Sciences, Kyungpook National University, Daegu 702-701, Korea b Department of Chemistry, Kyungpook National University, Daegu 702-701, Korea *e-mail: ycpark@mail.knu.ac.kr Received: August 18, 2005 Accepted: May 2, 2006 Abstract A dopamine (DA) polymer was deposited electrochemically on to a glassy carbon (GC) surface until the electrode surface was passivated. The DA film on the GC surface was re-formed for high sensitivity and reproducibility by electrochemical degradation. The re-formed electrode was sensitive and selective in the determination of DA in the presence of ascorbic acid. The linear range obtained by square-wave voltammetry was between 0.1 and 2.1 mM (R ¼ 0.996, n ¼ 6) with a sensitivity of 1.2 mA mM1 and a detection limit (S/N ¼ 3) of 0.04 mM. The electropolymerized DA film was stable and the re-formed electrode was reproducible for DA determination. Keywords: Dopamine film, Electrochemical degradation, Exposed GC surface, Dopamine, Ascorbic acid DOI: 10.1002/elan.200503536 1. Introduction been charged by modified films or by pretreatment were often used in a system of DA and AA [18 – 26]. In spite of the Abnormal levels of catecholamine neurotransmitter dop- high selectivity for DA, a DA film-modified electrode was amine (DA) results from a loss of pigmented DA neurons, inappropriate for DA determination because of its poor which can lead to neurodegenerative disorders [1 – 4]. DA is sensitivity and reproducibility [15]. We have considered an readily auto-oxidized or electroch