Synthesis of copper oxides-graphene composites for glucose sensing

Abstract

A multi-gram preparation of graphene nanoplatelets decorated with CuO leaf-like structures and Cu2O nanocubes can be accomplished with ease from graphite using an environmentally friendly method. The composites' synthesis is conveniently achieved within an hour through a high shear mixing pre-treatment of the graphite in water, followed by the addition of copper salts to the resulting slurry and their subsequent conversion to cupric or cuprous oxide-few layer graphite composites of varying weight ratios. The materials, characterized by XRD, Raman, SEM, TEM, and TGA exhibit good electrochemical glucose oxidation sensing capacity. Cyclic voltammetry of modified glassy carbon electrodes prepared with a 1:0.2 weight ratio of graphene nanoplatelets to CuO or Cu2O composites shows low detection limits of 0.25 μM (S/N = 3) for glucose and high sensitivities of 845 and 1,108 μA cm–2 mM–1, respectively. The sensors also show exceptionally low current response to the commonly found interferents such as uric acid, dopamine, and ascorbic acid. The materials' ease of manufacturing and good sensing capabilities suggests their potential use in determining glucose contents in biological samples and industrial applications.