Surface Selenylation Engineering for Construction of a Hierarchical NiSe₂/Carbon Nanorod: A High-Performance...

As glucose (Glu) is an essential substance for metabolism as well as a symbol to diagnose diabetes, the demand of Glu sensors has increased significantly in recent decades. In this work, a hierarchical Ni-based electrochemical enzyme-free Glu sensor, namely, NiSe₂/CNR (carbon nanorod), was engineered through a facile thermal treatment using dimethylglyoxime dinickel salt with selenium (Se) powder. The prepared NiSe₂/CNR not only subtly introduces a hierarchical structure with rod-like carbon nanorods and rock-like NiSe₂ nanoparticles, which are extremely helpful in offering a greater catalytic activity area and more catalytic active sites, but also incorporates the Se element to increase the inherent activity. The fabricated NiSe₂/CNR exhibits distinguished performance for Glu detection in alkaline electrolytes with linear ranges of 0.5-411 μM and 411 μM to 6.311 mM, high sensitivities of 3636 μA mM^-1 cm^-2 at low concentrations, and 2121 μA mM^-1 cm^-2 at high concentrations, as well as a low detection limit of 380 nM (S/N = 3). It also possesses favorable reproducibility, stability, and long-term storage capacity. The practical feasibility of NiSe₂/CNR was also validated by detecting Glu in human serum. Moreover, the prepared hierarchical NiSe₂/CNR is of general interest for the construction of hierarchical Ni-based sensors.