Nitrogen doped graphene quantum dots as a fluorescent probe for mercury(II) ions.


Key Laboratory of Optoelectronic Technology & Systems of the Education Ministry of China, College of Optoelectronic Engineering, Chongqing University, Chongqing, 400044, China. [Email]


A highly selective fluorescent probe for Hg2+ is reported. It consists of nitrogen doped graphene quantum dots (NGQDs) that are nearly spherical in shape, have an average diameter of 2.7 nm and excitation-independent emission. The blue fluorescence of the NGQDs (with maximum excitation/emission at 378/447 nm) is quenched by Hg2+ due to both dynamic and static quenching. The probe has a wide detection range (2.5 μM - 800 μM) and a limit of detection of 2.5 μM. The dynamic and static quenching constants are 417 M-1 and 63500 M-1, respectively. The probe was used to quantfy Hg2+ in spiked real water samples with satisfactory results. Graphical abstract ᅟ.


Fluorescence quenching,Fluorescent probe,Hg2+ detection,Modified Stern-Volmer equation,Nitrogen doped graphene quantum dots,Static and dynamic quenching,

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