Washable textile biosensors enabled by nanostructured oxides with fast ion diffusion

Textile-based electronics possess comfortable epidermal contact and the potential for wearable healthcare applications such as non-invasive sweat biosensing. However, achieving washable biosensors without sacrificing sensitivity and wearing comfort remains a challenge. Herein, we develop β-Bi₂O₃ nanoflakes, which enable washable textile-based biosensors. The β-Bi₂O₃ nanoflakes with fast ion conductivity possess high moisture stability without introducing large impedance. The incorporation of β-Bi₂O₃ nanoflakes improved the sensitivity and washability of textile ionic sensors for sodium, potassium, and proton sensing, with a performance retention of over 90% after 20 washing cycles. As a demonstration, we created a washable and reusable integrated electronic textile wristband for wireless sweat biomarker analysis. This work showcases the use of nanostructured oxides as a washing-resistive layer and a fast ion conductor to confer washability on textile-based sensing devices.