Hierarchical Cu/Cu(OH)2 nanorod arrays grown on Cu foam as a high-performance 3D self-supported electrode for enzyme-free glucose sensing

Abstract

Hierarchical Cu/Cu(OH)₂ nanorod arrays grown on commercially available Cu foam (Cu/Cu(OH)₂ NRA/CF) was prepared via a three-step strategy involving the wet chemical synthesis of Cu(OH)₂ NRA/CF, a chemical reduction reaction for conversion from Cu(OH)₂ NRA/CF to Cu NRA/CF, and finally galvanostatic anodization to grow Cu(OH)₂ nanoparticles on Cu NRA/CF. Hierarchical Cu/Cu(OH)₂ NRA/CF shows high catalytic activity towards glucose oxidation in an alkaline solution and can serve as a promising electrode material for enzyme-free glucose sensing. At an applied potential of +0.5 V, the sensor showed a broad detection range of 0.001–1.0 mM, a high sensitivity of 9.18 mA mM⁻¹ cm⁻², and a low detection limit of 0.45 μM (S/N = 3). Furthermore, the sensor exhibits excellent selectivity against common interferents and good reliability for glucose detection in human serum samples.