Non-enzymatic reusable graphene-based electrodes by a simple scalable preparation method and superior electrochemical property

Simple, applicable electrodes are the main features of electrochemical biosensors. Production of such electrodes using a time-consuming and non-expensive method was the aim of this study. According to this purpose, three-dimensional graphene foam (3DGF) was produced successively as an interconnected porous network of the high intrinsic surface area via a self-assembly method. Using Ag pastes as substrate, free-standing 3DGF electrodes as well as other graphene-based electrodes were prepared simply with high conductivity and desired electrochemical features. Any kind of additives including enzymes or functional groups or even, other nanomaterials as a hybrid was not used in the electrodes provided longer stability and less preparation time. A low cathodic current of -4.3 mA was measured in cyclic voltammograms (CV) of such small 3DGF electrodes (100 times less than previously reported glassy carbon (GC)-based electrodes). Non-enzymatic detection of H2O2 was clearly illustrated by a remarkable drop of the cathodic current, about 1.2 mA. Besides, the amperometric response of the 3DGF electrode certified the excellent reduction toward hydrogen peroxide with a correlation coefficient of more than 98%. The reusability of the 3DGF electrode was confirmed by less than 3% deviation in the cathodic current of particular electrodes after washing and repetitive use.