Deformable, transparent, high‐performance, room‐temperature oxygen sensors based on ion‐conductive, environment‐tolerant, and green organohydrogels

Abstract

Abstract We present green organohydrogel‐based stretchable (up to 700% strain), transparent, and room‐temperature O2 sensors with impressive performance, including drying and freezing tolerances, high sensitivity, broad detection range (100 ppm‐100%), long‐term stability, low theoretical detection limit (0.585 ppm), linearity, and the capability to real‐time monitor human respiration by directly attaching on human skin. A facile solvent replacement approach is employed to partially exchange water with natural and edible xylitol/sorbitol molecules, generating stable, green and tough organohydrogels. Compared with the pristine hydrogel counterpart, the organohydrogel‐based O2 sensors feature higher stability, prolonged life time (140 days) and the ability to work over a wide range of temperatures (−38 to 65°C). The O2 sensing mechanism is elucidated by investigating the redox reactions occurred at the electrode‐hydrogel interface. This work develops a facile strategy to fabricate stretchable, transparent, and high‐performance O2 sensor using stable and green organohydrogels as novel transducing materials for practical wearable applications.

Keywords

• anti‐freezing and anti‐drying hydrogel
• conductive and green organohydrogel
• redox reaction sensing mechanism
• stretchable and room‐temperature oxygen sensor
• xylitol and sorbitol