Tuning of Co3X4 (X = O, S, Se) by anion substitution for highly electrochemical sensing of glucose

Cobalt (Co) based nanomaterials are widely used to construct glucose enzyme-free electrochemical sensors. However, the correlation between anion species and the electrocatalytic activity of Co based nanomaterials remains unproven. In this paper, Co 3 X 4 with different anions (X = O, S, Se) were synthesized for electrochemical sensing of glucose. Co 3 X 4 was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), powder X-ray diffractometry (XRD), and electrochemical techniques. The results showed that anion substitution had a significant effect on the electrocatalytic properties of Co 3 X 4 , and Co 3 Se 4 showed the strongest electrocatalytic activity for the oxidation of glucose. The sensor based on Co 3 Se 4 exhibited excellent performance for glucose analysis with a linear range from 2 μM to 0.71 mM, a high sensitivity of 1327.6 μA mM −1 cm −2 and a low detection limit of 0.3 μM, which demonstrates Co 3 Se 4 as a new nonenzymatic electrocatalyst for glucose sensing.