Dual-Valence Copper Nanostructures with Cu⁺/Cu²⁺ Interfaces for High-Sensitivity Glucose Electrochemical Sensing

Copper-based materials, renowned for their redox versatility and conductivity, have extensive applications in electrochemical sensing. Herein, we construct stable Cu⁺/Cu²⁺ interfaces within dual-valence copper nanostructures to achieve enhanced sensitivity in glucose sensing. By employing a hydrolysis method to tune Cu²⁺/Cu⁺ ratios precisely, we achieved an optimal electrochemical interface with heightened stability and reactivity. The Cu⁺/Cu²⁺ interface-based flexible electrode demonstrated excellent glucose sensitivity (332.4 µA mmol/L^-1 cm^-2 at +0.65 V), wide linear range (up to 10 mmol), a low detection limit of 1.02 nmol/L, and strong selectivity, including detection in human sweat, making this study significant for advanced electrochemical sensors.