High-entropy doped oxide/Ti3C2Tx heterostructured fiber as flexible electrochemical sensor electrode for real-time sweat dopamine monitoring

Customizing smart clothing for monitoring the physiological and vital sign information in real time has raised demands for wearable sensors with rapid response, good stability, high sensitivity and excellent mechanical properties. Herein, a flexible high-entropy doped oxide Cu 0.9 Fe 0.06 Ni 0.01 Cr 0.01 Co 0.01 Mn 0.01 (HE-Cu 2 O) nanoparticle modified Ti 3 C 2 T x (HECT) fiber was prepared through a facile hydrothermal growth and heat treatment process. Due to rich active sites, high reactivity and large surface area, HE-Cu 2 O appears impressive detection ability, admired adsorption inclination and exceptional reaction kinetics, confirming by DFT calculation. What’s more, the covalent coupling between the Ti 3 C 2 T x conductive frameworks and HE-Cu 2 O nanoparticles can further avoid the negative influence of metal oxide on the electronic conductivity, ensuring fast electron transfer rate. As a result, the HECT fiber can be operated in DA/PBS solution with reliable electrocatalyst properties, including low detection limit (1 μM), rapid response rate (<2 s), remarkable long-term cycling performance (100 cycling) and excellent reproducibility (RSD ≈ 2.01 %). Additionally, when the HECT fiber, matching with the Ag/AgCl electrode and Pt wire, weaves into the garment, the integrated system retains obvious response level, less response time (<5 s) and outstanding electrocatalyst performance under dynamic situations (bending, running, rope skipping and doing yoga), demonstrating a potential in practical application.