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

Understanding how light dynamically regulates ascorbic acid (AA) levels is essential for improving crop nutritional quality. However, the dynamic regulation of AA by light in vivo 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.