Electrochemical glucose sensitive device based on graphene supported Co3O4@Ag NWs core-shell nanostructures

Abstract

We demonstrate the fabrication of Co3O4 (derived from zeolitic imidazolate framework-67) wrapped Ag nanowires core-shell nanostructures, and support it on graphene matrix (Co3O4@Ag NWs-GR) to prepare enzymeless glucose sensor. The core-shell Co3O4@Ag nanowires possess porous surface and the proposed Co3O4@Ag NWs-GR nanocomposites exhibit hierarchical structure which could help to improve the performance of enzyme-free glucose detection. For practical application, the as-prepared Co3O4@Ag NWs-GR nanocomposites were sandwiched by nickel foam (NF) to develop a glucose detection electrode, which demonstrates good reproducibility and glucose specific selectivity. Then, the Co3O4@Ag NWs-GR/NF electrode was integrated with Pt wire, Ag/AgCl wire and polydimethylsiloxane (PDMS) to fabricate a sensitive device. The amperometric response of the as-developed device suggests that the Co3O4@Ag NWs-GR/NF based sensor presents a high sensitivity of 2.49 μA/μM/cm2 in the linear interval of 3–2000 μM, a detection limit of 0.98 μM, as well as an outstanding long-term stability. Additionally, the human serum was used to verify that the Co3O4@Ag NWs-GR based glucose sensor can detect the glucose level in serum, suggesting it is applicable to the enzymeless glucose determination.