Nanodispersed aggregates of MnO2 were prepared in the aqueous core of the H2O/Aerosol OT (AOT)/heptane reverse micelle using the comproportionation reaction between MnO4- and Mn2+ ions. The formed nanoparticles were characterized by transmission electron microscopy (TEM), UV-visible spectroscopy and cyclic voltammetry. The electro-oxidation of dextrose and fructose on platinum modified by reverse micellar MnO2 deposits was studied. The oxidation of fructose was found to be much more facile than dextrose oxidation. There was a linear correlation between the steady state oxidation currents and the carbohydrate concentrations, which was shown to be useful for analytical application. The sensitivity for fructose detection was found to be about seven times higher than that of dextrose. The scope of developing an electroanalytical method for estimation of dextrose and fructose individually in their mixture was explored. (C) 2008 Elsevier B.V. All rights reserved.