ZnCo₂O₄ nanostructure-based electrochemical sensor for highly sensitive glucose detection

Enzyme-free electrochemical glucose sensors attract the attention of researchers due to their high reproducibility and stability compared to enzymatic sensors, which is of practical importance for both clinical diagnostics and the food industry. The development of an economical, controlled method for the synthesis of a multicomponent composite used to determine glucose is an urgent task for the prevention and treatment of diabetes. In this work, zinc cobaltite ZnCo2O4 nanostructures on nickel foam were synthesized using a simple hydrothermal method. The possibility of using the grown structures as a basis for enzyme-free electrochemical sensors for determining glucose is shown. It was revealed that the concentration of the growth solution affects the morphology of the synthesized structures and their electrochemical properties. The highest sensitivity to glucose 18.65 mA·mM-1·cm-2 in an alkaline solution of 0.1 M KOH was demonstrated by ZnCo2O4 samples grown in an aqueous solution containing 40 mM zinc nitrate and 400 mM cobalt nitrate. The results of the study show that the molar predominance of cobalt nitrate in the growth solution contributes to an increase in the electrochemical sensitivity of Ni-ZnCo2O4 electrodes. The obtained samples can be used as highly sensitive electrodes used both in medical applications and for the needs of the food industry.