Microelectrodes Modified with [MIII(bpy)3](ClO4)3 (M=Co and Fe) as Analytical Sensors for Fullerenes in Flow Injection Analysis

Autor: Tadeusz Krogulec, Piotr Diakowski, Krzysztof Winkler, Marta E. Plonska
Rok vydání: 2001
Předmět:
Zdroj: Electroanalysis. 13:1185-1190
ISSN: 1521-4109
1040-0397
DOI: 10.1002/1521-4109(200110)13:14<1185::aid-elan1185>3.0.co;2-0
Popis: Catalytic electroreduction of fullerene (C60) at Au or Pt microelectrodes covered with [MIII(bpy)3](ClO4)3 (M=Co and Fe, and bpy=2,2′-bipyridine) was investigated. Under constant potential oxidation in acetonitrile/toluene (1:4, v/v) solution containing [MII(bpy)3]2+ complexes and (n-Bu)4NClO4 as a supporting electrolyte, the microelectrodes were modified with electrochemically inactive [MIII(bpy)3](ClO4)3 films. The chemical reduction of electrochemically formed films by C−60 results in enhancement of fullerene reduction current enabling thus for sensing of C60. Analytical performance of electrodes modified with [CoIII(bpy)3](ClO4)3 was better than those covered with [FeIII(bpy)3](ClO4)3. Microelectrodes modified with [CoIII(bpy)3](ClO4)3 were used to quantify the fullerene concentration in flow injection analysis. In the proposed analytical procedure the solution containing both the [CoII(bpy)3]2+ complex and the C60 analyte was injected to the flowing stream of an acetonitrile/toluene (1:4, v/v) mixture containing (n-Bu)4NClO4. The triangular potential waveform was applied to the gold microelectrode. During the positively going potential scan the electrode was covered by an electrochemically inactive [CoIII(bpy)3](ClO4)3 layer. In the cathodic scan, the catalytic current of C60 reduction was recorded. A dependence of a current signal of catalytic C60 reduction on fullerene concentration was linear in a concentration range 5×10−7 to 2×10−5 mol dm−3. Reproducibility of the electrode response under FIA conditions was good.
Databáze: OpenAIRE
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