Two-Dimensionally Ordered Carbon Array Nanostructures with Atomically Dispersed Nickel for Sensitive Nonenzymatic Detection of Glucose

How to construct highly sensitive electrochemical sensors based on single atoms is one of the hotspots. In this study, we reported a strategy for regulating the electrocatalytic activity of nickel single atoms (Ni SAs) based on directional assembly, which could be used to construct a glucose electrochemical sensor. Nitrogen-doped two-dimensionally ordered array carbon nanostructures with atomically dispersed nickel (D-Ni SAs/CN) were synthesized by directional assembly of interconnected carbon polyhedrons via ionic exchange, ice templating, and high-temperature pyrolysis. The materials were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. Electrochemical results revealed that the ordered arrangement of carbon polyhedrons endowed the D-Ni SAs/CN with a stronger electrocatalytic effect on glucose oxidation than that of isolated nitrogen-doped carbon polyhedrons containing atomically dispersed nickel (Ni SAs/CN). The linear range for detecting glucose was 0.002–1.1 mM with a high sensitivity of 1418.7 μA·mM–1·cm–2 and a detection limit of 1.2 μM. Moreover, the sensor could be used to accurately measure glucose levels in real samples. This study not only demonstrated the feasibility of Ni SAs as an excellent sensing material but also highlighted the importance of two-dimensionally ordered carbon array nanostructures in enhancing the electrochemical sensing performance.