High-performance non-enzymatic glucose-sensing electrode fabricated by α-nickel hydroxide-reduced graphene oxide nanocomposite on nickel foam substrate

A non-enzymatic glucose-sensing material composed of α-nickel hydroxide nanosheets grown on reduced graphene oxide sheets (α-Ni(OH)₂-rGO) is fabricated by a straightforward co-precipitation method. The morphology and composition of the α-Ni(OH)₂-rGO are analyzed by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analyzer, and X-ray photoelectron spectroscopy. The characterization results show that the content of Ni(OH)₂ in the α-Ni(OH)₂-rGO composites is about 82.77 wt%. The introduction of rGO can effectively prevent α-Ni(OH)₂ from agglomeration. The thickness of the α-Ni(OH)₂ sheets grown vertically on the rGO is less than 10 nm, and they are interwoven to form a porous network structure. Then, the α-Ni(OH)₂-rGO/NiF (Nickel Foam)-sensing electrode is prepared with NiF as the substrate. The sensing mechanism and detection property of the α-Ni(OH)₂-rGO/NiF-sensing electrode are researched through cyclic voltammetry (CV) and amperometry. The test results demonstrate that α-Ni(OH)₂-rGO/NiF-sensing electrode has excellent glucose-sensing performance. Its linear detection range is as wide as 0.5–22.5 mM, and the sensitivity is as high as 95.5 μAmM⁻¹ cm⁻², which is obviously much better than previously studied glucose-sensing materials. Moreover, it is found that the prepared sensing electrode has excellent anti-interference and stability. After repeated measurements, the anodic peak current is only 6% lower than the initial current. More importantly, the sensing electrode also showed a good detection ability for actual samples, which fully confirms that α-Ni(OH)₂-rGO/NiF-sensing electrode has good practical application potential.