Carbon Nanotubes paste electrodes. Analytical applications

GUSTAVO A. RIVAS; M. LAURA PEDANO; MARIA D. RUBIANES

Tesalónica

Congreso; 55º ISE Meeting; 2004

International Society of Electrochemistry

This communication reports on the advantages of a new electrode obtained by the incorporation of gold nanoparticles into a graphite composite as well as on the analytical applications for the quantification of bioanalytes. The influence of the size and percentage of nanoparticles in the composite material on the electrochemical response was evaluated. Hydrogen peroxide, catechol and dopamine were used as índicators. Important enhancements of the oxidation currents and shifting of the peak potentials were observed in the presence of gold nanoparticles. However, the most significant effect was obtained when some protein is incorporated into the composite material. This excellent catalytic effect of the nanoparticles dispersed into graphite paste modified with proteins represents a very interesting avenue for analytical applications, especially connected with the development of enzymatic biosensors. The response of graphite paste electrodes modified with gold nanoparticles and glucose oxidase has allowed us to obtain a large improvement in the sensitivity of the electrode towards glucose. The incorporation of polyphenol oxidase also allowed a very significant increase in the sensitivity of the resulting bioelectrode towards catechol and dopamine. Therefore, the proposed material associates the advantages of the composite materials with the catalytic effect of gold nanoparticles, opening the doors to new electrode materials and new designs of biosensors.