Flexible non-enzymatic glucose biosensor based on CoNi₂S₄ nanosheets grown on nitrogen-doped carbon foam substrate

A flexible non-enzymatic glucose sensing material which consists of the CoNi₂S₄ nanosheets grown on the reticular Nitrogen-doped Carbon Foam substrate (CoNi₂S₄@NCF) has been successfully fabricated by a simple two-step synthesis process. The micromorphology, composition and valence of the CoNi₂S₄@NCF are researched by means of FESEM, TEM, XPS and XRD. Subsequently, the glucose sensing characteristics of the CoNi₂S₄@NCF are studied by Cyclic Voltammetry and Amperometry, and the detection performance of CoNi₂S₄@NCF synthesized by different processes is compared. Through a series of tests, it is found that when the volume ratio of deionized water to anhydrous ethanol is 30 ml: 30 ml, the prepared CoNi₂S₄@NCF has excellent glucose sensing properties. The sensitivity is 6.675 μA mM⁻¹ cm⁻² and 54.82 μA mM⁻¹ cm⁻² over the linear detection range of 0.5–12.5 mM and 12.5–30 mM, respectively. At the same time, the CoNi₂S₄@NCF has outstanding anti-interference, stability, repeatability and shows good performance in the detection of actual samples. In addition, the synthesized CoNi₂S₄@NCF has good flexibility and compressibility. Compared with general sensing materials, this flexible material is more conducive to storage and use. It provides a new idea for wearable instruments. All these fully indicate that the fabricated CoNi₂S₄@NCF have a good prospect in the field of non-enzymatic glucose sensing.