Flexible Graphene substrates for electrochemical analysis and construction of functional nanostructures

Graphene as a highly conductive, adsorptive, and structurally flexible material has been widely employed to develop advanced electronic devices and sensors. In this study, by simply drop-casting the desired amount of industrial grade, graphene nano-platelets onto conventional double-sided conductive tape, we developed a convenient, versatile, and scalable graphene substrate (namely, flexible graphene substrate in a snap) with much-improved in-plane conductivity for electrochemical analysis and template-assisted deposition of functional nanostructures. Particularly cyclic voltammetric measurements with reversible redox couples showed ideal responses on such "flexible graphene electrodes" with superior reproducibility and stability. The quantitation of medically relevant, trial analysts (i.e., ascorbic acid and dopamine) showed excellent linearity in established calibration curves (R-2 > 0.995) and satisfactory detection sensitivity. More remarkably, by affixing nano-porous templates (polycarbonate or AAO membranes) onto these flexible graphene substrates, we can fabricate various metallic nanostructures via a conventional benchtop electrode position process, which exhibit excellent electro-analytical (Au nano-clusters as ideal ultramicroelectrode arrays) and catalytic activities (Pt nanowires towards modulated H2O2 reduction). Beyond the application of quantitative electrochemical analysis and bench-top creation of functional nanostructures, we envision that such "flexible graphene substrate in a snap" as a versatile, scalable platform material can be adapted to many other designs of graphene-based sensors and analytical devices. (C) 2021 Elsevier Ltd. All rights reserved.