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Electrochemical Overoxidation of Polyindole and Its Cation‐Permselective Behavior
Author(s) -
Ghita Mihaela,
Arrigan Damien W. M.
Publication year - 2004
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.200302938
Subject(s) - cyclic voltammetry , dichloromethane , chemistry , electrochemistry , aqueous solution , monomer , carboxylate , voltammetry , electrode , inorganic chemistry , chemical engineering , polymer , organic chemistry , solvent , engineering
Polyindole films prepared by potentiostatic growth in dichloromethane solution were subjected to overoxidation studies in aqueous media. Overoxidation at potentials greater than 1.1 V (vs. SCE) in 0.1 M KNO 3 or 0.1 M H 2 SO 4 was possible. Overoxidation in 0.1 M NaOH resulted in mechanically unstable films which were not adherent to the electrode surface. The overoxidation process in 0.1 M KNO 3 involved removal of one electron per four indole monomer moieties in the polymer film. Nucleophilic attack led to introduction of carboxylate functionality and to cation permselective behavior, as tested by cyclic voltammetry and hydrodynamic voltammetry of hexamminoruthenium(III) and hexacyanoferrate(III). Such films may be useful in various electrochemical sensor applications.