A novel ball-in-ball hollow NiCo2S4 sphere based sensitive and selective nonenzymatic glucose sensor

Abstract

In this work, we developed a low-cost and sensitive electrochemical sensor for nonenzymatic detection of glucose based on ball-in-ball hollow ternary nickel cobalt sulfide spheres (NiCo₂S₄). A facile anion exchange method to synthesize the hollow structure of NiCo₂S₄ is demonstrated. The synthesized hollow NiCo₂S₄ was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical sensing properties of NiCo₂S₄ towards glucose were evaluated. Due to the synergetic effects from both Ni and Co species with multiple valence transitions and the high surface area of the hollow NiCo₂S₄, the nanostructure exhibited good performance towards glucose oxidation. A simple and selective sensing platform for the assay of glucose has been developed in 0.1 M KOH solution at 0.55 V. The sensor displays a wide linear range from 0.005 to 2 mM with a detection limit of 2 μM for glucose detection. For the determination of glucose in serum samples, the results are satisfactory when compared to those obtained from a local hospital.