Bipolar Pulse-Driven Flexible Ionogel Sensor with Superior Stability and Sensitivity for Wireless Trace Oxygen Detection

Oxygen is vital for human health, industrial and agricultural production, yet current oxygen sensors often exhibit limitations such as short lifespans or insufficient sensitivity at room temperature. Herein, a room-temperature oxygen sensor based on ionogel is fabricated using a bipolar pulse driving method, featuring superior stability and sensitivity. Ionogel is environmentally stable, avoiding issues such as freezing and dehydration in extreme conditions while maintaining good flexibility. Compared to traditional method, the bipolar pulse method mitigates degradation by repairing anode morphology through reversible reactions, achieving sustained performance for over 7 months. Furthermore, the short sampling time of the method achieves high sensitivity (405.71 nA/%), ultra-wide detection range (200 ppb-100% O₂), and reaches a stable baseline remarkably quickly (14.4 s, a 50-fold acceleration). The underlying mechanism, rooted in a reversible single-electron redox reaction, is elucidated through experimental validation and density functional theory calculations. The broad applicability of this strategy is also demonstrated, suggesting its potential to enhance performance across diverse electrode–electrolyte systems. This portable and flexible sensor, combined with Bluetooth and cloud-sharing technologies, presents its practical utility in wearable transcutaneous oxygen pressure monitoring, smart food packaging, and remote plant physiology monitoring, offering an innovative approach for developing advanced sensors for demanding applications.