▎ 摘　　要

A facile, economical, and green method has been developed to prepare a new fluorescent sensor based on ligninsulfonate/graphene quantum dots (SL/GQDs) core/shell hybrids for label-free sensitive and selective detection of Fe3+. The combination of these two materials brings both excellent photoluminescent properties (the fluorescence intensity of SL/GQDs composites is four times higher than the free GQDs) and nice selectivity. In this composite, SL molecule plays two key roles in the system as a pi-rich and sulfur incorporated compound to enhance the fluorescence and as a chelator to detect Fe3+. The obtained sensor presents excellent sensitivity and selectivity toward Fe3+ and exhibits a good linearity in the range of 0.005-500 mu M with a detection limit as low as 0.5 nM. We have further explored the practical use of such proposed probe for Fe3+ determination in lake water samples, which shows promise in environmental determination. (C) 2015 Elsevier B.V. All rights reserved.