Osmium Redox Polymer Film Electrode and Its Electrocatalytic Properties towards the Oxidation of Epinephrine: Electrochemical Quartz-Crystal Microbalance and Voltametric Characterization

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• 作者：J. J. Fei and S. S. Hu
• 关键词：amperometry ; osmium redox polymer ; electrocatalysis ; epinephrine
• 刊名：Russian Journal of Electrochemistry
• 出版年：2005
• 出版时间：December 2005
• 年：2005
• 卷：41
• 期：12
• 页码：1296-1304
• 全文大小：124 KB

文摘

An osmium redox polymer PVI-PAA-dmeOs is electrodeposited onto a gold electrode by using repetitive double potential step chronoamperometry. The resulting film is permeable to the substrates and products of the catalyzed reaction, and permits fast electron transfer. The frequency variation during the potential step process is recorded using electrochemical quartz-crystal microbalance (EQCM). A reaction mechanism for electrochemical deposition of the osmium redox polymer is proposed. The characteristics of the PVI-PAA-dmeOs film are investigated by EQCM and cyclic voltametry. The results show the hydrated osmium PVI-PAA-dmeOs film to exhibit excellent electrocatalytic activity towards the oxidation of epinephrine. At a bare gold electrode, the epinephrine oxidation current increases greatly and the oxidation peak potential negatively shifts to about 0.16 V (Ag/AgCl) at the film-modified electrode. Under optimal conditions, amperometric measurements are performed at 0.18 V and the current response of epinephrine changes linearly with its concentration from 5 ¡Á 10−7 to 1 ¡Á 10−4 mol l−1. A detection limit of 1.5 ¡Á 10−7 mol l−1 (S/N = 3) is obtained.