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Congo Red Immobilized on a Silica/Aniline Xerogel: Preparation and Application as an Amperometric Sensor for Ascorbic Acid
Author(s) -
Pavan Flávio André,
Schwingel Ribeiro Emerson,
Gushikem Yoshitaka
Publication year - 2005
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.200403132
Subject(s) - ascorbic acid , amperometry , carbon paste electrode , aniline , electrochemistry , electrode , inorganic chemistry , cyclic voltammetry , adsorption , congo red , chemistry , chemically modified electrode , nuclear chemistry , materials science , working electrode , organic chemistry , food science
Abstract Congo red (CR) was immobilized on a silica/aniline xerogel through electrostatic interaction. The dye is strongly retained and is not easily leached from the xerogel matrix. The material containing the adsorbed dye was used to prepare a carbon paste electrode and the electrochemical properties of the hybrid material were investigated using cyclic voltammetry and amperometry. The modified electrode was used to study the electrochemical oxidation of ascorbic acid. The adsorbed dye mediates ascorbic acid oxidation at the solid electrode surface‐solution interface at an anodic potential of 0.18 V at pH 7, in a 0.5 mol L −1 KCl solution. This novel modified carbon paste electrode shows good analytical performance for the determination of ascorbic acid in commercial Vitamin C tablets.