Topographic Characterization of Disposable Carbon Pencil Modified Electrodes

 

J. Berbejillo,^a J. Laiz,^a M.F. Cerdá,^b M.E. Martins,^c E. Méndez^b,*

 

^a) Unidad de Bioquímica Analítica. Centro de Investigaciones Nucleares, Facultad de Ciencias. Universidad de la República, Montevideo, Uruguay.

^b) Laboratorio de Biomateriales. Instituto de Química Biológica. Facultad de Ciencias, Universidad de la República. Iguá 4225 casi Mataojo. 11400 Montevideo, Uruguay.

^c) Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Universidad Nacional de La Plata, Provincia de Buenos Aires, Argentina.

 

Received 23 March 2004; accepted in revised form 31 May 2004

 

 

Abstract

Carbon pencil electrodes are proposed as supporting material for the fabrication of disposable devices through surface modification by bismuth plating and polyaniline formation. The surface characteristics were assessed by fractal analysis under semi-infinite linear diffusion employing a soluble molecular probe, and scanning electron microscopic analysis. The results indicate that the surface topography for bismuth-modified electrodes corresponds to a 2-dimensional smooth surface, while for polyaniline-modified electrodes, a surface fractal dimension of 2.76 was obtained. These topographic characteristics indicate that bismuth-modified carbon electrodes are suitable for anodic stripping analysis, and polyaniline ones, due to the surface irregularities, may result a good supporting material for biomolecules attachment.

 

Keywords: carbon pencil electrodes, fractals, Randles-Sevcik, topography.

 

 

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* Corresponding author. E-mail address: emendez@fcien.edu.uy