The carbon dots as colorimetric and fluorescent dual-readout probe for 2-nitrophenol and 4-nitrophenol detection

Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.