Characterization of carrageenan hydrogel electrode coatings with immobilized cationic metal complex redox couples

Journal Article (Journal Article)

The redox behavior of cationic metal complexes immobilized in a κ-carrageenan hydrogel matrix, which acts as a cation-exchange polymeric electrode coating, is described. Ru(bpy)32+, Ru(en)33+, Ru(NH3)63+, and Co(bpy)33+ (bpy = 2,2′-bipyridine; en = ethylenediamine) were immobilized singly and in pairs (Ru(bpy)32+ and Co(bpy)33+) on the surface of a Pt electrode and were characterized by cyclic voltammetry. The redox couples were selected on the basis of their structural similarity and wide range of electron self-exchange rate constants (101-109 M-1 s-1). The surface-modified carrageenan hydrogel electrode was found to exhibit superior electrolyte diffusion properties when compared with more commonly used cation-exchange immobilization matrices such as Nafion, and to be stable with respect to leakage of cations into the solution. The carrageenan hydrogel film was also found to be permeable to anionic redox couples such as Fe(CN)63-/4-. All immobilized redox couples exhibited quasi-reversible electrochemical behavior. Evidence supporting a dual-mode mechanism involving physical diffusion and electron hopping for charge propagation through the carrageenan hydrogel is presented. © 1992 American Chemical Society.

Full Text

Duke Authors

Cited Authors

  • Crumbliss, AL; Perine, SC; Edwards, AK; Rillema, DP

Published Date

  • January 1, 1992

Published In

Volume / Issue

  • 96 / 3

Start / End Page

  • 1388 - 1394

International Standard Serial Number (ISSN)

  • 0022-3654

Digital Object Identifier (DOI)

  • 10.1021/j100182a067

Citation Source

  • Scopus