Catalyst-Free Efficient Growth, Orientation and Biosensing Properties of Multilayer Graphene Nanoflake Films with Sharp Edge Planes

Authors


  • We acknowledge supports from the European Union under the DESYGN-IT project (STREP Project 505626-1) and the National Centre for Electron Spectroscopy and Surface (NCESS) analysis at Daresbury Laboratory, UK. We thank R. McCann and A. Kumar in University of Ulster for their help in the X-ray photoelectron spectroscopy measurement. Supporting Information is available online from Wiley InterScience or from the author.

Abstract

We report a novel microwave plasma enhanced chemical vapor deposition strategy for the efficient synthesis of multilayer graphene nanoflake films (MGNFs) on Si substrates. The constituent graphene nanoflakes have a highly graphitized knife-edge structure with a 2–3 nm thick sharp edge and show a preferred vertical orientation with respect to the Si substrate as established by near-edge X-ray absorption fine structure spectroscopy. The growth rate is approximately 1.6 µm min−1, which is 10 times faster than the previously reported best value. The MGNFs are shown to demonstrate fast electron-transfer (ET) kinetics for the Fe(CN)63−/4− redox system and excellent electrocatalytic activity for simultaneously determining dopamine (DA), ascorbic acid (AA) and uric acid (UA). Their biosensing DA performance in the presence of common interfering agents AA and UA is superior to other bare solid-state electrodes and is comparable only to that of edge plane pyrolytic graphite. Our work here, establishes that the abundance of graphitic edge planes/defects are essentially responsible for the fast ET kinetics, active electrocatalytic and biosensing properties. This novel edge-plane-based electrochemical platform with the high surface area and electrocatalytic activity offers great promise for creating a revolutionary new class of nanostructured electrodes for biosensing, biofuel cells and energy-conversion applications.

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