A glucose electrode constructed with three-dimensional wrinkled graphene loaded on nickel foam, engineered to augment the Debye screening length

Nanomaterial-based electrochemical sensors enable real-time detection of chemical and biological parameters, with advantages including cost-effectiveness, high selectivity, high sensitivity, and portability. However, their detection sensitivity is drastically reduced in liquids due to the Debye screening effect. This paper investigates a Co₃O₄/CuS/rGO electrode for glucose detection: Co₃O₄ is obtained via annealing, while CuS and 3D wrinkled graphene are synthesized by hydrothermal method. Polyvinylpyrrolidone (PVP) is used during reduced graphene oxide (rGO) preparation to prevent graphene oxide sheet aggregation. Additionally, adding a biomolecule-permeable, porous polymer layer to the sensor extends the effective screening length near the device surface, enabling real-time glucose detection in high-ionic-strength fluids. The sensor exhibits a glucose detection range of 0.10–500 μM, sensitivity of 84.18 μA·mM⁻¹·cm⁻², signal-to-noise ratio (SNR) of 3, and detection limit of 0.046 μM. This study provides a valuable insight for applying nanomaterial-based electrochemical sensors in sweat glucose detection, which could become a powerful tool for basic research and medical applications.