Self-healable and stretchable electrochemical sensor for sweat glucose detection

Wearable sensing devices provide a promising approach for non-invasive health detection. However, most flexible devices are inevitably susceptible to wear and mechanical degradation in practical applications due to stretching, cutting, or overuse, resulting in device malfunction. Therefore, it is necessary to develop sensing devices with self-healing and stretchable capabilities. Here, an in-situ self-healing and stretchable sweat glucose sensor is fabricated by depositing Au on the synthetic self-healable PDMS_0.9-IPDI elastomer and modifying polypyrrole/glucose oxidase on the sensing position, respectively. This sensor can recover electromechanical properties through dynamic hydrogen bonds after fracture and self-healing 4 h at room temperature, and maintain stable sensing properties under 50 % strain, which satisfies the strain required by human skin in daily activities. In addition, the modified polypyrrole film on the Au electrode increases the electrochemically active area of the working electrode by 3-4 times and the sensor exhibits a sensitivity of 62.60 μA mM^-1 cm^-2 in the linear range of 0-1 mM, with the detection limit is as low as 12.58 μM. Furthermore, the sensor can accurately and reliably detect the glucose content in human sweat samples, providing a novel approach for the practical application of glucose sensors.