Magnetic-field-induced acicular nickel immobilized on carbon nanofibers as electrodes for electrochemical glucose sensing

Background: Effective high-throughput strategies to prepare nanostructured electrodes for glucose sensing remain significant interest for many applications. In this study, acicular nickel was immobilized on carbon nanofibers (CNFs) via electroless plating under a magnetic field to form CNFs-Ni, and its application as an electrode in amperometric non-enzymatic glucose sensing was investigated. Methods: Polyacrylonitrile (PAN) nanofibers (NFs) were fabricated by centrifuged-electrospinning, in which the combination of electrostatic and centrifugal forces produces a strong stretching force. PAN polymer chains were aligned parallel to the axis of the NFs, thereby stretching the dispersed PAN droplets into thin and molecularly orientated NFs. The PAN NFs were then subjected to stabilization followed by carbonization at 1200, 1300, 1400, or 1500 °C to produce PAN CNFs. The characteristics of the CNFs were confirmed by scanning electron microscopy (SEM), electron spectroscopy for chemical analysis, Raman spectroscopy, and four-point probe analysis. Additionally, the CNFs coated with acicular nickel (CNFs-Ni) were analyzed by SEM, X-ray diffraction, and high-resolution transmission electron microscopy. Significant Findings: Under the optimal conditions (CNFs1400-Ni), the glucose sensor showed a high sensitivity (7404 μA mM⁻¹ cm⁻²) with a linear range from 2.1 × 10⁻² to 6.0 × 10⁻¹ mM (R² = 0.993) and fast response (10 s).