Electrooxidation and determination of dopamine using a Nafion (R)-cobalt hexacyanoferrate film modified electrode

• Autor(a) principal: Castro, Suely S. L.
• Data de Publicação: 2008
• Outros Autores: Mortimer, Roger J., de Oliveira, Marcelo F., Stradiotto, Nelson Ramos [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• DOI: 10.3390/s8031950
• Texto Completo: http://dx.doi.org/10.3390/s8031950; http://hdl.handle.net/11449/42352
• topic: cobalt hexacyanoferrate; chemically modified electrode; dopamine; voltammetry; rotating disk electrode

The electrocatalysis of dopamine has been studied using a cobalt hexacyanoferrate film (CoHCFe)-modified glassy carbon electrode. Using a rotating disk CoHCFe-modified electrode, the reaction rate constant for dopamine was found to be 3.5 x 105 cm(3) mol(-1) s(-1) at a concentration of 5.0 x 10(-5) mol L-1. When a Nafion (R) film is applied to the CoHCFe-modified electrode surface a high selectivity for the determination of dopamine over ascorbic acid was obtained. The analytical curve for dopamine presented linear dependence over the concentration range from 1.2 x 10(-5) to 5.0 x 10(-4) mol L-1 with a slope of 23.5 mA mol(-1) L and a linear correlation coefficient of 0.999. The detection limit of this method was 8.9 x 10(-6) mol L-1 and the relative standard deviation for five measurements of 2.5 x 10(-4) mol L-1 dopamine was 0.58%.