It is critical for fabricating flexible biosensors with both high sensitivity and good selectivity to realize real-time monitoring superoxide anion (O₂^•−), a specific reactive oxygen species that plays critical roles in various biological processes. This work delicately designs a Mn₃(PO₄)₂/MXene heterostructured biomimetic enzyme by assembling two-dimensional (2-D) Mn₃(PO₄)₂ nanosheets with biomimetic activity and 2-D MXene nanosheets with high conductivity and abundant functional groups. The 2-D nature of the two components with strong interfacial interaction synergistically enables the heterostructure an excellent flexibility with retained 100% of the response when to reach a bending angle up to 180°, and 96% of the response after 100 bending/relaxing cycles. It is found that the surface charge state of the heterostructure promotes the adsorption of O₂^•−, while the high-energy active site improves electrochemical oxidation of O₂^•−. The Mn₃(PO₄)₂/MXene as a sensing platform towards O₂^•− achieves a high sensitivity of 64.93 µA·µM⁻¹·cm⁻², a wide detection range of 5.75 nM to 25.93 µM, and a low detection limit of 1.63 nM. Finally, the flexible heterostructured sensing platform realizes real-time monitoring of O₂^•− in live cell assays, offering a promising flexible biosensor towards exploring various biological processes.

制造具有高灵敏度和良好选择性的柔性生物传感器对于实现实时监测超氧阴离子（O ₂ ^•-）是至关重要的，这是一种特殊的活性氧，在各种生物过程中都起着至关重要的作用。这项工作通过组装二维（2-D）Mn ₃（PO ₄）₂精心设计了Mn ₃（PO ₄）₂ / MXene异质仿生酶。具有仿生活性的纳米片和具有高电导率和丰富官能团的二维MXene纳米片。具有强界面相互作用的两个组件的2D性质协同作用使异质结构具有出色的柔韧性，当达到180°的弯曲角度时，保留了100％的响应，在100个弯曲/松弛周期后保留了96％的响应。发现异质结构的表面电荷状态促进了O ₂ ^•的吸附，而高能活性位点改善了O ₂ ^•的电化学氧化。Mn ₃（PO ₄）₂ / MXene作为对O ₂ ^•−的传感平台实现了64.93 µA·µM ^-1 ·cm ^-2的高灵敏度，5.75 nM至25.93 µM的宽检测范围和1.63 nM的低检测限。最后，灵活的异质结构传感平台可在活细胞测定中实现O ₂ ^•的实时监控，为探索各种生物过程提供了一种有前途的灵活生物传感器。