Highly stable non-enzymatic glucose sensor based on ternary NiCoFe-layered hydroxide grown on graphene oxide

Abstract

Here, ternary layer hydroxide (NiCoFe-LDH) nanosheets have been grafted in situ onto graphene oxide (GO) using a one-pot hydrothermal method to obtain NiCoFe-LDH/GO for the fabrication of a non-enzymatic glucose sensor with high stability. SEM analysis shows that ternary LDHs with a nanosheet layer structure grow on GO at an angle with less stacking, thus imparting NiCoFe-LDH/GO with a large specific surface area (112.32 m² g⁻¹) that exposes more active sites. The results of cyclic voltammetry (CV) and chronoamperometry (CA) studies show that NiCoFe-LDH/GO/GCE displays a wide linear detection range of 0.005–7.54 mM, a sensitivity of 196.18 μA cm⁻² mM⁻¹, and a low detection limit of 0.41 μM (S/N = 3). In particular, NiCoFe-LDH/GO/GCE has high stability, that is, it still holds 90.2% of its initial value even after 90 days. Meanwhile, the study results demonstrate that the NiCoFe-LDH/GO/GCE electrode is suitable for the detection of glucose in artificial saliva, and it also reveals a good recovery ranging from 95.6% to 105.5% in actual saliva. Therefore, NiCoFe-LDH/GO is anticipated to be an ideal sensing material for the creation of noninvasive enzyme-free glucose sensors.