Fluorescent sensing of rutin by carbon dots derived from the heart of cumin seeds

Carbon dots (CDs) prepared from biomass usually produce poor quantum yield and reproducibility. A fine separation of raw materials may enhance the fluorescence performance. In this work, embryos of cumin seeds were precisely chosen as the carbon source to prepare (CDs) through hydrothermal method. The obtained product (CDs-E) possessed a higher quantum yield of 10.60 % than those synthesized with testas or whole seeds, which may be due to the relatively smaller particle size and more C-N functional groups. Rutin, as a common natural active component, could quench the fluorescence of CDs-E notably through internal filtering effect. Herein, a highly selective fluorescent sensor based on CDs-E for detecting rutin was proposed with a linearity range of 0.05 ∼ 30 μM and a detection limit of 0.015 μM obtained. Additionally, the developed method was successfully applied for the detection of rutin in Flos Sophorae , rutin tablets and capsules. This work showed the significance of fine classification for natural carbon source in preparation of CDs and provided a feasible method for quality monitoring of rutin-related pharmaceuticals, health care products and traditional Chinese medicinal materials.