The parallel fluorescence determination of iron(III), terbium(III) and europium(III) ions using the coal-derived carbon dot

This paper reports a simple, rapid and sensitive fluorescence sensor for the parallel determination of iron (III) (Fe 3+ ), terbium (III) (Tb 3+ ) and europium (III) (Eu 3+ ) ions using Carbon Dot (CD) serving as a fluorescence probe. The Carbon Dot (CD), which was synthesized via an acid-cutting method using anthracite coal as the carbon source, was found to have rich carboxyl and hydroxyl groups on its surface. The fluorescence of the as-prepared CD can be selectively quenched by the Fe 3+ ion via non-radiative electron-transfer, and furthermore, the as-prepared CD can also sensitize the luminescence of both Tb 3+ and Eu 3+ ions through the antenna effect and enhance the fluorescence of Tb 3+ and Eu 3+ by more than several orders of magnitude. Therefore, the as-prepared CD was applied as a fluorescence probe towards the parallel determination of Fe 3+ , Tb 3+ and Eu 3+ and exhibited detection limits in 0.019, 0.10 and 0.79 μM, respectively. The fluorescence quenching mechanism and energy transfer mechanism were also studied in details.