▎ 摘　　要

Although graphene-based materials have a number of excellent properties, their permselective properties have not yet been reported. In this work, graphene oxide (GO) and its reduced form (rGO) with the C:O ratios of 2.3:1 and 10.5:1, respectively were coated on glassy carbon electrodes (GCES) and subsequently evaluated by cyclic voltammetry and an adsorption method assuming a Langmuir isotherm behavior. The GO and rGO films allow the permeation of neutral ferrocenemethanol (FcOH) and cationic Ru(NH3)(6)(3+) but restrict the permeation of anionic Fe(CN)(6)(4-) across their layers. The adsorption of FcOH and Ru(NH3)(6)(3+) within the GO and rGO films leads to the preconcentration at the electrode surface and subsequently enhances redox currents of FcOH (Fe(II)/Fe(III)) and Ru(NH3)(6)(3+) (Ru(III)/Ru(II)). Gibbs free energy changes of Fc0H and Ru(NH3)(6)(3+) adsorbed within GO and rGO films are -21 to -26 kJ mol(-1). The electrooxidation of hydrazine at the modified electrodes was also studied to demonstrate the potential application of the modified electrodes. The linear ranges of hydrazine detection with R-2 of 0.999 are 0.004-1.8 mM and 0.02-1.8 mM for rGO/GCE and GO/GCE, respectively. Limits of detection at a signal-to-noise ratio of 3 are 0.4 and 0.9 mu M for rGO/GCE and GO/GCE, respectively. (C) 2013 Elsevier Ltd. All rights reserved.