Sensitive “On‐Off” Fluorescent Sensor From N‐Doped Carbon Dots for Fe3+ Detection and Anticounterfeiting Applications

ABSTRACT Herein, a kind of N‐doped fluorescent carbon dots (N‐CDs) were prepared by using melamine and carboxymethyl cellulose (CMC) as precursors through a straightforward hydrothermal method. The designed sensor displayed a uniform nanoscale distribution, excellent hydrophilicity, and strong fluorescence emission with a fluorescence quantum yield of 37.98%. Moreover, the N‐CDs could be utilized for Fe 3+ detection by the fluorescence “On–Off” transition via the mechanism of internal filtration effect (IFE) and static quenching process. Two good linear relationships within the concentrations of Fe 3+ from 10 to 100μM and 100 to 500 μM could be obtained, which indicated that the “On–Off” fluorescent sensor could quantitative analysis of Fe 3+ and the calculated detection limit (LOD) was 0.510 μM (3σ/slope). Additionally, the N‐CDs could be used for the detection of Fe 3+ in the solid phase based on the fluorescence “On–Off” strategy, which is promising for anticounterfeiting application.