Microwave-assisted synthesis of graphene modified CuO nanoparticles for voltammetric enzyme-free sensing of glucose at biological pH values

Abstract

The effect of graphene nanosheets on the glucose sensing performance of CuO powders was investigated. CuO and graphene-modified CuO nanoparticles (NPs) were fabricated by microwave-assisted synthesis and characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The material was placed on a glassy carbon electrode (GCE) which then was characterized by cyclic voltammetry and chronoamperometry with respect to the capability of sensing glucose both at pH13 and pH7.4. The results revealed that the modified GCE has a fast and selective linear response to glucose at pH13 that covers the 0.21μM to 12mM concentration range, with a 0.21μM low detection limit. The presence of graphene nanosheets results in an improved sensitivity which is to 700μA mM-1cm-2. In solution of pH7.4, the respective data are a linear analytical range from 5 to 14mM; a 5μM LOD and a sensitivity of 37.63μA mM-1cm-2 at working potential of -0.05V (vs. Ag/AgCl) and scan rate of 50mV s-1. Ascorbic acid, dopamine, uric acid, sucrose, maltose and fructose do not interfere. Graphical abstract ᅟ.