Fluorescent nitrogen-doped carbon dots as nanosensors for the detection of Fe${}^{3+}$ ions

Fluorescent nitrogen-doped carbon dots (N-CDs) are obtained by a straightforward hydrothermal method, and tartaric acid and L-histidine hydrochloride are used as precursors. The obtained N-CDs exhibit nanoscale structure, good water solubility, photostability, and excellent fluorescence (FL) properties with a high FL quantum yield of 19%. The designed N-CDs are used as fluorescent probes for detecting Fe${}^{3+}$ with the FL "on-off" strategy. Two good linear relationships can be observed for the concentration of Fe${}^{3+}$ from 0 to 80 µm and from 80 to 600 µm, and the calculated detection limit for Fe${}^{3+}$ is 0.88 µm (3σ/slope). Moreover, the N-CDs-based FL probe can also be used for detecting Fe${}^{3+}$ in tap water and possesses great potential application in the field of anti-fake information encryption. (© 2023 Wiley‐VCH GmbH)