Implantable Fiber Sensor for Continuous Monitoring of Light-Regulated Ascorbic Acid Dynamics

remains unclear, since conventional methods rely on destructive sampling and only provide static data. To address this, we develop an implantable fiber sensor functionalized with a dual-atomic nanozyme for minimally invasive, long-term tracking of AA in living plants. The implantable fiber sensor integrates a hierarchical nanobio interface composed of a Co-Fe dual-atomic nanozyme (CoFe-DAzyme) and an antifouling hydrogel, achieving a detection limit of 0.081 μM in plant bleeding sap and remaining functional for up to 7 days postimplantation. Employing this sensor in lettuce, we uncover rapid, light-dependent AA fluctuations, directly revealing how dynamic light environments fine-tune this key nutritional metabolite. Our work not only establishes a versatile sensing platform but also provides direct mechanistic insight into the light-regulated improvement of crop nutritional quality.