Tri. Cataldi et al., Electrocatalysis and amperometric detection at a ruthenium-modified indium-hexacyanoferrate film electrode, ELECTROANAL, 10(17), 1998, pp. 1163-1167
The electrocatalytic activity of a glassy carbon electrode modified with el
ectrochemically deposited indium(III)-hexacyanoferrate (InHCF) film, which
has been subsequently cycled in a solution of ruthenium(III), is described.
Although the resulting ruthenium-modified InHCF thin film electrode behave
s in a manner analogous to the parent InHCF film, its stability was found t
o be greatly improved. Such a modified electrode was characterized, in acid
ic (pH 2) 0.5 M KCl solutions, by cyclic voltammetry and flow injection ana
lysis. It exhibits a high catalytic activity for the electrooxidation of so
me some inorganic and organic compounds of analytical interest, such as As(
III), S2O32-, cysteine, and 2-furaldehyde. The analytical applicability of
this novel ruthenium-modified InHCF film electrode for the amperometric det
ection in flowing streams is discussed. Repetitive sample injections with a
mperometric detection of thiosulfate at +0.8 V (vs. Ag/AgCl) as applied pot
ential produced a stable response over 8 h of operation, making it very att
ractive for practical applications.