{Reference Type}: Journal Article
{Title}: Coffee grounds-derived carbon quantum dots as peroxidase mimetics for colorimetric and fluorometric detection of ascorbic acid.
{Author}: Zhu Y;Deng X;Chen J;Hu Z;Wu F;
{Journal}: Food Chem
{Volume}: 429
{Issue}: 0
{Year}: 2023 Dec 15
{Factor}: 9.231
{DOI}: 10.1016/j.foodchem.2023.136957
{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.