Glucose Biosensor Based on the Use of Carbon Nanotubes Paste Electrode Modified with Metallic Particles

G. L. LUQUE; FERREYRA N. F.; G. A. RIVAS

Microchimica acta

Springer-Verlag

Lugar: Austria; Año: 2006 vol. 152 p. 277 - 283

This work reports on the performance of new glucose biosensors based on the combination of the electrocatalytic properties of metals and carbon nanotubes towards the reduction of hydrogen peroxide with the biocatalytic activity of glucose oxidase (GOx). The bioelectrodes were obtained by dispersing the metal particles, enzyme and multi-wall carbon nanotubes within a mineral oil binder. The strong electrocatalytic activity of copper and iridium towards the reduction of hydrogen peroxide has made possible an important improvement in the sensitivity for the determination of glucose compared to the carbon nanotubes composite without metals. In fact, a highly sensitive and selective amperometric detection of glucose has been obtained at very low potentials (-0.100 V). The presence of the protein has permitted a better dispersion of the metals within the composite matrix allowing an additional enhancement in the response of the bioelectrode to hydrogen peroxide. The influence of the amount of copper in the composite on the analytical performance of the bioelectrode is discussed. The resulting biosensor containing 0.77 % w/w Cu and 10.0 % w/w GOx have shown a fast response (10.0 sec), a linear relationship between current and glucose concentration up to 1.20 x 10-2 M and a detection limit of 2.0 x 10-5 M. A similar behavior was obtained with the carbon nanotubes-composite electrode containing iridium.