Metal-organic framework–assisted bimetallic Ni@Cu microsphere for enzyme-free electrochemical sensing of glucose

The distinctive bimetallic metal-organic framework based on Cu@Ni microsphere with a solid ball-like structure is successfully synthesized by a two-step hydrothermal reaction. Their structural morphology and bimetallic composition are characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), respectively. The as-prepared bimetallic Cu@Ni organic framework can be modified on the glassy carbon electrode (GCE) and used for the non-enzymatic glucose sensor in an alkaline solution that exhibits better electrocatalytic activity relative to the individual material. The electrochemical analysis demonstrated that the developed sensor had superior electrocatalytic activity towards glucose oxidation, it exhibits a high sensitivity of 496 μA.mM⁻¹ in the range from 0 to 5 mM, limit of detection (LOD) of 0.4 μM and excellent selectivity with the signal to noise ratio (S/N) of 3. The superior catalytic performance towards glucose is mainly supported by the synergistic effect of Cu and Ni MOF. The fabricated glucose sensor also provided good performances in the investigation of real samples. Exploring different insights into the development of a new MOF based bimetallic nanostructure non-enzymatic glucose sensor with reasonable cost and good stability.