荧光碳点的绿色合成及其对镉胁迫下豌豆幼苗的毒性缓解效应OACHSSCD

The pollution of heavy metal cadmium(Cd2+)seriously threatens plant growth,and there is an urgent need to develop efficient strategies for detecting and mitigating the toxicity of cadmium.This study synthesized a type of carbon dots(CDs)with selective fluorescence response to Cd2+via a calcination method using 5-amino-1,10-phenanthroline and salicylic acid as raw materials.The fluorescence intensity of CDs exhibited a good linear relationship with Cd2+concentration in the range of 0-100 µmol/L,with a detection limit as low as 0.3 µmol/L.Further experiments with pea seedlings revealed the stress-mitigating effects of CDs.The study found that under 400 mg/L Cd²⁺ stress,exogenous application of 0.5 mg/mL CDs reduced Cd2+accumulation in roots and stems by 48.2%and 72.4%,respectively,while significantly restoring the root length,shoot length,and biomass.Mechanistic studies demonstrated that CDs effectively mitigated Cd2+-induced oxidative damage and physiological metabolic disorders by enhancing chlorophyll levels,optimizing photosynthetic parameters,boosting antioxidant enzyme activity,and promoting carbohydrate accumulation.This study not only provides a novel approach for highly sensitive Cd2+detection but also reveals the synergistic role of CDs in reducing heavy metal uptake and improving stress resistance in plants,offering theoretical foundation and technical support for its application in environmental remediation and agricultural production.