Direct electrochemical reduction of graphene oxide on ionic liquid doped screen-printed electrode and its electrochemical biosensing application

A novel electrochemical biosensing platform using electrochemically reduced graphene oxide (ER-GNO) modified electrode was proposed. This modified electrode was prepared by one-step electrodeposition of the exfoliated GNO sheets onto the ionic liquid doped screen-printed electrode (IL-SPE). The resulting ER-GNO/IL-SPE brought new capabilities for electrochemical devices by combining the advantages of ER-GNO and disposable electrode. Two important biomolecules, nicotinamide adenine dinucleotide (NADH) and hydrogen peroxide (H2O2), were employed to study the electrochemical performance of the ER-GNO/IL-SPE, which exhibited more favorable electron transfer kinetics than the bare IL-SPE. On the basis of the greatly enhanced electrochemical reactivity of H2O2 at the developed electrode, ER-GNO and glucose oxidase constructed disposable biosensor showed better analytical performance for the glucose detection compared with the IL-SPE based biosensor. The linear range for the detection of glucose was from 5.0 mu M to 12.0 mM with a detection limit of 1.0 mu M. This work provides a useful avenue for implementing ER-GNO as a new generation of electrochemical transducer in disposable electrode, which could expand the scope of graphene constructed electrochemical biosensing devices and hold great promise for routine sensing applications. (C) 2011 Elsevier B.V. All rights reserved.