Green synthesis of fluorescent carbon quantum dots for the detection of mercury(II) and glutathione

Herein, we report a green synthetic approach for the synthesis of water-soluble fluorescent CQDs via a simple one-step hydrothermal treatment using Tamarindus indica leaves for the first time. The prepared CQDs show an excitation-dependent behavior in the range from 260 to 400 nm with a high QY of approximately 46.6%. Further, the prepared CQDs serve as a very sensitive nanoprobe for the turn-off sensing of Hg2+ with a minimum LOD as low as 6 nM in the dynamic range from 0 to 0.1 mu M. The attractiveness of the present sensing system is that it further acts as a turn-on sensor for GSH detection with good selectivity. The feasibility of the present sensing system is also examined using pond water samples for the detection of Hg2+. Thus, the present sensing system is reliable for sensing and several another analytical applications.