Eosinophilic nitrogen-doped carbon dots derived from tribute chrysanthemum for label-free detection of Fe³⁺ ions and hydrazine

A facile, green and economic one-step hydrothermal synthesis route using widely available tribute chrysanthemum as the new carbon and nitrogen precursors towards N-doped carbon nanodots (N-CDs) is proposed. The obtained N-CDs can be employed as acidophilic fluorescent sensor for label-free sensitive and selective detection of Fe³⁺ in a strong acid environment with a detection limit as low as 0.001 µM. In addition, the as-prepared N-CDs contain distinctive [sbnd]COOH groups and pyridyl nitrogen atoms on their surfaces. We further demonstrate that such wholly new N-CDs can serve as an effective fluorescent sensing platform for hydrazine. This environmentally friendly strategy offers a simple and efficient approach for preparing C-dots doped with heteroatoms from biomass in large-scale and lays a foundation for its further environmental applications.