Metal-organic framework-derived yolk-shell hollow Ni/NiO@C microspheres for bifunctional non-enzymatic glucose and hydrogen peroxide biosensors

Reliable determination of hydrogen peroxide (H2O2) and glucose is vital in various fields, especially implicated in diagnosis of diabetes and oxidative stress-related diseases. Herein, yolk-shell hollow Ni/NiO@C microspheres were template-synthesized with well-defined Ni-MOF (metal-organic framework) and further worked as a bifunctional electrocatalyst for glucose oxidation in alkaline solution and H(2)O(2)reduction in neutral solution, of which the unique structure and rich pore openings provide large accessible surface areas, while the uniformly distributed Ni, NiO and C efficiently catalyze and facilitate the reaction of glucose and H2O2, thus achieving a wide linear range of 0.01 to 10 mM with a sensitivity of 1291 mu A mM(-1) cm(-2)and a detection limit of 0.116 mu M for glucose and offering a sensitivity of 32.09 mu A mM(-1) cm(-2), a detection limit of 0.9 mu M and a linear range up to 80.7 mM for H2O2, as well as good selectivity, excellent reproducibility and long-term stability for two analytes. What's more, the as-constructed sensors realize quantitative detection glucose in blood serum with satisfying results and can use to monitor H(2)O(2)in neutral situation. This work opens an avenue to design high-performance sensoring materials but also becomes a great candidate in practical application.

Automated summary

In this study, yolk-shell hollow Ni/NiO@C microspheres were successfully template-synthesized using Ni-MOF, displaying a unique structure with rich pore openings. The microspheres were used as a bifunctional electrocatalyst for glucose oxidation and H2O2 reduction, showing wide linear ranges, high sensitivity, and the ability to quantitatively detect glucose in blood serum and monitor H2O2 in neutral situations.