Highly\nSensitive and Selective Nonenzymatic Detection\nof Glucose Using Three-Dimensional Porous Nickel Nanostructures

Abstract

Highly sensitive and selective nonenzymatic\ndetection of glucose\nhas been achieved using a novel disposable electrochemical sensor\nbased on three-dimensional (3D) porous nickel nanostructures. The\nenzyme-free sensor was fabricated through in situ growing porous nickel\nnetworks on a homemade screen-printed carbon electrode substrate via\nelectrochemically reducing the Ni²⁺ precursor, along with\ncontinuously liberating hydrogen bubbles. The resulting nickel-modified\nelectrode was characterized by scanning electron microscopy (SEM),\ntransmission electron microscopy (TEM), energy-dispersive X-ray spectrometry\n(EDX), powder X-ray diffractometry (XRD), and electrochemical techniques.\nCyclic voltammetric, alternating-current impedance, and amperometric\nmethods were used to investigate the catalytic properties of the assembled\nsensor for glucose electro-oxidation in alkaline media. Under optimized\nconditions, the enzymeless sensor exhibited excellent performance\nfor glucose analysis selectively, offering a much wider linear range\n(from 0.5 μM to 4 mM), an extremely low detection limit (0.07\nμM, signal-to-noise ratio (S/N) of 3), and an ultrahigh sensitivity\nof 2.9 mA/(cm² mM). Importantly, favorable reproducibility\nand long-term performance stability were obtained thanks to the robust\nframeworks. Application of the proposed sensor in monitoring blood\nglucose was also demonstrated.