Abstract：
In this study, we reported the eco-responsible synthesis of iron-doped carbon quantum dots (Fe-CQDs) from waste coffee grounds through a simple hydrothermal method. The Fe-CQDs exhibited high peroxidase-like activity, which could convert 3,3\',5,5\'-tetramethylbenzidine (TMB) into blue ox-TMB in the presence of H2O2. After adding ascorbic acid (AA) to above system, the blue solution faded. Based on this phenomenon, a colorimetric method for visual monitoring of H2O2 and AA was developed. Meanwhile, the fluorescence of Fe-CQDs can be quenched by the formed ox-TMB via inner filter effect (IFE), followed by the recovery upon the addition of AA. Therefore, Fe-CQDs can be acted as a fluorescent probe to detect H2O2 and AA through the \"on-off-on\" mode. Furthermore, the dual-recognition methods based on Fe-CQDs were used to measure AA content in beverage samples. Thus, this work would shed much light on converting waste into biomass CQDs and their potential applications in biomolecular detection.
摘要：
在这项研究中,我们报道了通过简单的水热法从废咖啡渣中生态负责合成铁掺杂的碳量子点（Fe-CQDs）。Fe-CQDs表现出高的过氧化物酶样活性，可以转换3,3\'，5,5'-四甲基联苯胺(TMB)在H2O2存在下变成蓝色ox-TMB。向上述体系中加入抗坏血酸(AA)后，蓝色溶液褪色。基于这种现象,开发了一种比色法视觉监测H2O2和AA。同时,Fe-CQDs的荧光可以通过内滤波效应(IFE)被形成的ox-TMB猝灭，然后在添加AA时进行回收。因此,Fe-CQDs可以作为荧光探针，通过“开-关-开”模式检测H2O2和AA。此外，基于Fe-CQDs的双重识别方法用于饮料样品中AA含量的测量。因此，这项工作将为将废物转化为生物质CQDs及其在生物分子检测中的潜在应用提供很多启示。
