Facile synthesis of hierarchical coral reef-like Cu2O/rGO nanocomposite for highly sensitive non-enzymatic glucose sensor

Abstract

In the present work, a non-enzymatic glucose sensor was fabricated using the hierarchical coral reef-like Cu2O/ reduced graphene oxide (rGO) nanocomposite, which was prepared via a simple chemical deposition method. The morphology and structure of the prepared nanocomposites were studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction method (XRD), and FT-IR.. The results indicate Cu2O/rGO nanocomposites show a hierarchical coral reef-like structure that Cu2O nanoclusters are uniformly distributed over the rGO substrate, which are composed of granules with a diameter about 30-50 nm. The well - distributed Cu2O nanoparticles on the surface of rGO provide more active sites for the catalytic redox reaction and significantly enhance the transfer of ions and electrons. The electrochemical behaviors of the Cu2O/rGO/GCE sensor are analyzed using cyclic voltammetry (CV), amperometric techniques and electrochemical impedance spectroscopy (EIS) in an alkaline medium. The Cu2O/rGO/GCE exhibited excellent glucose - sensing performance with high sensitivity (856.5 μA mM - 1 cm - 2), a wide linear range (0.001 to 4.41 mM), splendid reproducibility (RSD of 2.9%), and admirable anti - interference properties. It has been successfully applied to the determination of glucose in human blood serum with recoveries ranging from 96.6% to 102.0%. These results suggest that the Cu2O/rGO/GCE is an outstanding non-enzymatic sensor for the detection of glucose.