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Nafion‐coated carbon fiber for acetylcholine and choline sensors
Author(s) -
Navera Eriberta Nepomuceno,
Suzuki Masayasu,
Tamiya Eiichi,
Takeuchi Toshifumi,
Karube Isao
Publication year - 1993
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140050105
Subject(s) - choline oxidase , nafion , ascorbic acid , amperometry , cyclic voltammetry , acetylcholine , choline , selectivity , electrode , chemistry , chromatography , membrane , microelectrode , inorganic chemistry , electrochemistry , organic chemistry , biochemistry , catalysis , food science , acetylcholinesterase , enzyme , endocrinology , medicine
A major improvement in the selectivity of carbon fiber microelectrodes for acetylcholine (Ach) and choline (Ch) as cationic amines is described. The electrodes are coated with Nafion, a perfluorosulfonated polymer. This coating is practically impermeable to ascorbic acid (AA) and anionic biogenic amine metabolites. Nafion‐coated fiber was characterized by cyclic voltammetry (CV). Selectivity and the dynamic range of these coated electrodes were evaluated using amperometric determination at a fixed potential of 1.2 V. The esterase activity was determined using choline sensor, and the relative slope values showed a fast response between 1 and 3 minutes. Calibration plots for Ach and choline showed a linearity range between 0.1 and 3 mM, with an increase of two orders of magnitude better than the previously used PVA‐SbQ membrane. No response was obtained between 0.1 and 0.3 mM of AA conc. The procedure, in preparing this type of coated electrodes, indicates some attractive perspectives for its use, especially for in vivo monitoring.