Superficial Edge Effect of N2-Doped Nanodiamond on the Highly Stable Nonenzymatic Glucose Detection Properties of Dispersed Graphene Flakes/Ni Nanostructures.

Abstract

In this study, we report nitrogen-doped nanodiamond (ND)-integrated crushed graphene (Gr) nanoflakes on nickel hydroxide (Ni(OH)2, named NH) nanostructures for highly stable nonenzymatic glucose sensors. A chemical vapor deposition route with a simple hydrothermal method was devised in the fabrication of ND-Gr-NH nanostructures. Thus, the results depict that the best sensitivity of 13769 μA mM-1 cm-2 was detected for Gr-NH, while NH shows 10,358 μA mM-1 cm-2. The salient improvement in the sensitivity of ND-Gr-NH is 15,431.2 μA mM-1 cm-2, with a limit of detection of 0.1 μm. The enhancement in ND-integrated Gr-NH is due to the synergistic influence of ND and graphene on NH. Furthermore, the ND-Gr-NH electrode shows a good stability (95%), while Gr-NH exhibits a stability of 82% over 21 days. In addition, the present ND-based electrode shows high selectivity toward glucose among additional interfering compounds including sodium chloride (NaCl), uric acid, and ascorbic acid. These outstanding enzymeless glucose sensing results could be ascribed to the synergistic influence that provides more active sites and further enhances the electron-transfer reaction.