Weavable, large-scaled, rapid response, long-term stable electrochemical fabric sensor integrated into clothing for monitoring potassium ions in sweat

• PPVN-EFS can realize K + detection in sweat with large-scale for garment integration. • The warp and weft of PPVN-EFS can achieve absorbing sweat in skin sensing area by interaction. • PPVN-EFS can achieve rapid respond (≤2.1 s) and long-term stable sensing (≥ 6000 s). Currently, most electrochemical sensors use thin films, single fiber or yarn as sensing unit. However, the weaving process remains challenging along with properties such as a large sensing area, rapid response and long-term stable monitoring. Herein, an electrochemical fabric sensor was developed based on a skin-core structured sensing yarn for in-situ monitoring of potassium ion (K + ) concentrations in human sweat and this was achieved through a simple but novel electro-assisted core spinning technique (EACST). The nanofibers in the skin layer of the induction yarn showed excellent hydrophilicity and high specific surface area (8.85 m 2 /g) as well as significant differences in hydrophilicity and hydrophobicity of the warp and weft yarns of the fabric. As such, they could achieve absorption of sweat limit domain in the skin sensing area, so that the sensor can respond quickly within a short time (2.1 s) and achieve long-term stable sensing (above 6000 s). In addition, the sensor exhibited excellent selectivity, potential reproducibility as well as low noise and signal drift (3.6 × 10 -2 mV/s). The large-area (55 cm × 35 cm) of the electrochemical fabric sensor could also be sewn into clothing for integration onto the human body where it could effectively collect sweat for real-time in-situ monitoring of K + signals in human sweat.