Pitch-derived carbon quantum dots as fluorescent probe for selective and sensitive detection of ferric ions and bioimaging

Carbon quantum dots (CQDs) emerging as newcomers of carbon nanoparticles exhibit fascinating electro-optical properties, and thereby have been widely used in many fields. Herein, we present a new facile, economical and environmentally attractive strategy for the preparation of CQDs via one-step ozone (O3) treatment of coal tar pitch (CTP). CQDs prepared by this approach exhibit a narrow size distribution between 3?7 nm, and CQDs with a diameter of 4.8 nm accounts for approximately 42.8 %. CQDs were investigated as fluorescent probes for the detection of metal ions, and demonstrated highly sensitive and selective detection of Fe3+ ions. A calibration curve displayed a linear response over the range of 0?9 ?M and a detection limit of 0.02 ?M (1.12 ppb). Moreover, the photoluminescence performance of the CQDs/Fe3+ complex could be recovered with the addition of EDTA, indicating a great potential for applications of this unique fluorescent CQDs in the detection of Fe3+. Finally, the experiments of CQDs in cell imaging confirmed that the CQDs can be used as potential fluorescent probes in biological imaging, cell labeling with strong luminescence and low toxicity.