Electrochemistry at CVD Grown Multilayer Graphene Transferred onto Flexible Substrates

The application of graphene and graphene-related materials for the fabrication of improved electrochemical devices is a very active research field. Because of the need of bulk quantities of graphene for such applications, chemical vapor deposition (CVD) represents one of the most promising fabrication processes to obtain large area and good quality graphene films with controlled thickness. Here we investigated the electrochemical properties of a multilayer graphene film grown by CVD and transferred to an insulating flexible poly(ethylene terephthalate) (PET) sheet. After a careful characterization with optical microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy of the transferred graphene film, we tested its heterogeneous electron transfer properties with Fe(CN)(6)(3-/4-) and Ru(NH₃)(6)(2+/3+) redox mediators and its sensing capability toward dopamine (DA), ascorbic acid (AA), and the reduced form of beta-nicotinamide adenine dinucleotide (NADH) as biological relevant molecules. The CVD grown multilayer graphene film transferred to a PET substrate showed an electrochemical behavior that resembles that of basal plane graphite with a low density of edge-plane defects sites. The possibility to retain electrochemical properties of graphene after the transfer to flexible and insulating supports is of high importance for the fabrication of novel electrochemical devices.