Département de chimie moléculaire

This paper describes the heterogeneous electron transfer (ET) properties of high-quality multilayer graphene (MLG) films grown using CVD on Ni and transferred to insulating poly(ethylene terephthalate) (PET) sheets. An O plasma treatment was used to enhance the ET properties of the films by generating oxygenated functionalities and edge-plane sites and defects. SEM, Raman, and XPS along with voltammetry of the std. redox probes [Ru(NH3)6]3+/2+, [Fe(CN)6]3-/4-, and Fe3+/2+ were used to demonstrate this effect. The biol. relevant mols. dopamine, NADH, ascorbic acid, and uric acid are employed to show the improved sensing characteristics of the treated films. Control expts. involving com. available edge-plane and basal-plane pyrolytic graphite (EPPG and BPPG) electrodes help to explain the different responses obsd. for each probe, and in certain cases, treated MLG provides a viable alternative to EPPG, hitherto considered to be the best-case scenario in C electrochem. This is the 1st comprehensive study of the electroanal. properties of pristine and functionalized CVD-grown MLG, and it will serve as an important benchmark in the clarification of ET behavior at graphene surfaces, with a view to the development of novel electrochem. sensors. [on SciFinder(R)]