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International Journal of Electrochemistry
Volume 2011, Article ID 697698, 8 pages
http://dx.doi.org/10.4061/2011/697698
Research Article

Electrocatalytic Reduction of Hydrogen Peroxide on Palladium-Gold Codeposits on Glassy Carbon: Applications to the Design of Interference-Free Glucose Biosensor

1Department of Physical Chemistry, Plovdiv University, 24 Tsar Assen Street, 4000 Plovdiv, Bulgaria
2Department of Inorganic and Physical Chemistry, University of Food Technology, 26 Maritsa Boulevard, 4002 Plovdiv, Bulgaria

Received 29 March 2011; Accepted 17 May 2011

Academic Editor: Newton Pimenta Neves Jr.

Copyright © 2011 Elena Horozova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Following our previous studies on the catalytic activity electrochemically codeposited on graphite Pd-Pt electrocatalysts for hydrogen peroxide electroreduction, a series of glassy carbon electrodes were modified with Pd or (Pd+Au) deposits aiming at the development of even more efficient electrocatalysts for the same process. The resulting electrodes were found to be very effective at low applied potentials (100 and 50 mV versus Ag/AgCl, 1 M KCl). The surface topography of the electrode modified with Pd+Au mixed in proportions 90% : 10%, exhibiting optimal combination of sensitivity and linear dynamic range towards hydrogen peroxide electrochemical reduction, was studied with SEM and AFM. The applicability of the same electrode as transducer in an amperometric biosensor for glucose assay was demonstrated. At an applied potential of 50 mV, the following were determined: detection limit (S/N=3) of 6×106 M glucose, electrode sensitivity of 0.15 μA μM1, and strict linearity up to concentration of 3×104 M.