Strategies for Cr(VI) Detection and Cell Imaging Using Yellow Fluorescence N-doped Carbon Dots.

Herein, multifunctional fluorescent N-doped carbon dots (N-CDs) are synthesized from O-phenylenediamine and 4-aminobenzoic acid. Hydrothermal synthesis and nitrogen doping make the N-CDs possess good physical and chemical properties with bright emission at 567 nm (QY = 32%) and present obvious excitation dependence. Among common metal ions, only Cr(VI) strongly and linearly decrease the yellow fluorescence of N-CDs in wide concentration ranges of 20.0-180 µM and 180-350 µM. Thus, N-CDs are constructed as efficient fluorescence probe for Cr(VI) with detection limit of 1.94 µM. The mechanism of quenching is indicated as the inner filter effect (IFE). The proposed sensor has been successfully applied in two kinds of water samples. In addition, the CDs are tried to apply for cell imaging. Above experiments prove that N-CDs based sensors are efficient strategies for sensitive Cr(VI) detection and cell imaging.