Morphology-Dependent Electrochemical Sensing Properties of NiCo2O4 for Glucose

Abstract

The morphology of nanomaterials plays an important role in the electrochemical sensing performance. Herein, the morphology-dependent electrochemical sensing properties of NiCo2O4 for glucose were studied. NiCo2O4 with one-dimensional (1D) rod structure or two-dimensional (2D) sheet structure was synthesized by just changing solvent composition. The morphology, structure and electrochemical sensing performance of NiCo2O4 were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometric methods. The results of CV characterization show that the magnitude of the oxidation peak current increase obtained on rod-like NiCo2O4 is nearly two times higher than that of sheet-like NiCo2O4, which is due to the faster electron transfer rate of rod-like NiCo2O4. Rod-like NiCo2O4 exhibited higher electrocatalytic activity toward glucose oxidation with a wide linear range of 0.02–5.1[Formula: see text]mM, a low detection limit of 2.0[Formula: see text][Formula: see text]M and an ultrahigh sensitivity of 2040[Formula: see text][Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]mM[Formula: see text][Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]. Our findings offer a novel morphology-controllable synthesis strategy to understand the morphology impact on the electrochemical performances of NiCo2O4, and represent a facile design of electrocatalysts for sensors.