A facile synthesis of magnetic fluorescence Fe3O4-carbon dots for the detection and removal of Hg2+

This article reports a one-pot hydrothermal strategy for preparing fluorescence carbon dots with magnetic properties (Fe3O4-CDs). Ammonium ferric citrate (AFC) and urea served as the iron and nitrogen sources and both as carbon sources were put into the reaction solvent diethylenetriamine (DETA), which acted as a reductant and nitrogen provider in the process of the synthesis of Fe3O4-CDs. Further, a sensitive and rapid method based on the Fe3O4-CDs was utilized for the detection of Hg2+, simultaneously accompanied with a magnetic removal process. Good linearity was obtained in the range from 2.0 to 200.0 nM with a detection limit of 12.6 nM. The fluorescence quenching mechanism was proved to be caused by an inner-filter effect (IFE) and static quenching effect (SQE). More, this platform was successfully applied for the analysis of Hg2+ in a real sample with satisfying recovery results, thus demonstrating its utility as a convenient monitoring strategy.