Fluorescent Nitrogen‐Doped Carbon Dots as Nanosensors for the Detection of Fe3+ 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 Fe3+ with the FL “on‐off” strategy. Two good linear relationships can be observed for the concentration of Fe3+ from 0 to 80 μm and from 80 to 600 μm, and the calculated detection limit for Fe3+ is 0.88 μm (3σ/slope). Moreover, the N‐CDs‐based FL probe can also be used for detecting Fe3+ in tap water and possesses great potential application in the field of anti‐fake information encryption.