Carbon dots-based fluorescence enhanced probe for the determination of glucose

In this work, a novel "turn-on" fluorescence sensor for the detection of H₂O₂ and glucose was developed based on green fluorescent carbon dots (CDs). The CDs was newly prepared by a facile one-pot hydrothermal method with Eosin Y and branched polyethylenimine as precursors. Interestingly, in the presence of H₂O₂ and HRP, the fluorescence of the CDs enhanced significantly with a red-shift emission due to their "aggregation". Meanwhile, the oxidation of glucose catalyzed by glucose oxidase could generate H₂O₂. Thus, a simple sensing system based on the CDs as fluorescent probes was constructed for H₂O₂ and glucose determination, avoiding the fluorescence quenching and subsequent recovery process in conventional turn-on strategy. The method showed good selectivity and sensitivity for glucose sensing with the detection limit of 0.12 μM. The method was further applied to glucose detection in real samples. The obtained results demonstrated the simplicity, selectivity and practicality of the method. This work expands the carbon nanomaterials with fluorescence emission enhancement properties. It provides a new and direct "turn-on" strategy for H₂O₂ and glucose detection, which could be a simple and effective tool for screening biological substances involved in H₂O₂-generation reaction.