Preparation and glucose sensing performance of network-like nanoporous Au/AuCu@TiCuAu composite electrodes

To overcome the challenges of high cost and low catalytic activity commonly observed in non-enzymatic glucose sensors, a three-dimensional bicontinuous network-like nanoporous Au/AuCu@TiCuAu composite electrode was successfully fabricated via anodic polarization in an ethylene glycol electrolyte containing 0.2wt.% NH₄F and 2.0vol.% H₂O with a trace-gold-containing amorphous Ti₆₀Cu₃₈Au₂ ribbon acting as dealloying precursor. The as-fabricated electrode consists of an amorphous TiCuAu substrate and an interconnected nanoporous layer of Au and AuCu phases. Electrochemical characterization revealed that the NP Au/AuCu@TiCuAu electrode exhibits a rapid response, high current density, and excellent cycling stability toward glucose oxidation in alkaline solution. A wide linear detection range from 1 to 10 mmol/L was achieved with an outstanding correlation coefficient(R² = 0.995), a sensitivity of 31 μA·cm⁻²·(mmol/L)⁻¹, and a low detection limit of 46 μmol/L(S/N = 3). Furthermore, the electrode displayed superior selectivity against common interfering species such as dopamine (DA), glycine (Gly), ascorbic acid (AA), uric acid (UA), and formic acid (FA). The NP Au/AuCu@TiCuAu electrode shows a great potential for practical applications in non-enzymatic glucose sensors and blood glucose monitoring systems. This work provides a novel and cost-effective approach for the design and application of high-performance nanoporous metallic electrodes.