Sensitive, rapid, and continuous detection of hydrogen peroxide (H₂O₂) is of great importance in many systems for quality control, healthcare products, medical diagnostics, food safety, and environmental protection. Yet, the continuous monitoring of H₂O₂ remains challenging due to the cost, lack of specificity, and bulkiness of current H₂O₂ sensor technologies. These challenges are exacerbated for applications where the sensor must be fully submerged in a liquid media. In this work, a highly flexible hydrogel-based electrochemical sensor is constructed for reliable and ultrasensitive detection of H₂O₂ in liquid environments. The hydrogel-based H₂O₂ sensors are based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the transducer, hydrophilic polyurethane (HPU) as the hydrogel matrix, and horseradish peroxide (HRP) as the H₂O₂ specific redox enzyme. The sensors have a dual-mode sensing mechanism, namely amperometric and chemiresistive sensing. Benefited from co-redoxing of PEDOT:PSS and HRP, the sensors exhibit high stability, fast response (<6 s), and high selectivity against common interferences, as well as a detection range from 100 µM to 101.6 mM in amperometric mode or 613 nM to 6.13 mM in chemiresistive mode. The hydrogel-based sensors are stable in liquid environments without leaching of PEDOT:PSS after a 2-month storage period in an aqueous media.

过氧化氢 (H ₂ O ₂ ) 的灵敏、快速和连续检测在质量控制、保健产品、医疗诊断、食品安全和环境保护的许多系统中都非常重要。然而，由于当前 H ₂ O ₂传感器技术的成本、缺乏特异性和体积庞大，对 H ₂ O _{2的连续监测仍然具有挑战性。}对于传感器必须完全浸没在液体介质中的应用，这些挑战更加严重。在这项工作中，构建了一种高度灵活的基于水凝胶的电化学传感器，用于可靠和超灵敏地检测 H ₂ O ₂在液体环境中。基于水凝胶的 H ₂ O ₂传感器基于聚 (3,4-乙烯二氧噻吩):聚苯乙烯磺酸盐 (PEDOT:PSS) 作为传感器，亲水性聚氨酯 (HPU) 作为水凝胶基质，辣根过氧化物 (HRP) 作为传感器H ₂ O ₂特定的氧化还原酶。传感器具有双模式传感机制，即电流传感和化学电阻传感。得益于 PEDOT:PSS 和 HRP 的共氧化还原，传感器表现出高稳定性、快速响应 (<6 s) 和对常见干扰的高选择性，以及在电流模式或 613 下从 100 µM 到 101.6 mM 的检测范围在化学电阻模式下 nM 至 6.13 mM。基于水凝胶的传感器在液体环境中稳定，在水性介质中储存 2 个月后不会浸出 PEDOT:PSS。