Green synthesis of carbon dots by celery leaves and used as fluorenscent paper sensors for detection of nitrophenol
Herein, natural celery leaves and glutathione was used as precursors to prepare carbon dots (CDs), as a novel fluorescent and paper sensor CDs exhibited high sensitivity and selective detection for explosive nitrophenol (including 2-nitrophenol (2-NP), 3-nitrophenol (3-NP) and 4-nitrophenol (4-NP)). The prepared CDs featured blue fluorescence emission under irradiation of an UV lamp and the fluorescence quantum yield was as high as 53%. As a fluorescent probe, the CDs possessed particular response to 2-NP, 3-NP and 4-NP, the detection limit of 2-NP, 3-NP and 4-NP was determined at 39 nM, 43 nM and 26 nM, respectively. Getting multiple advantages including good water solubility, low toxicity and excellent stability, the CDs are expected to be widely used. Meanwhile, CDs based test paper was exploited and displayed distinctive quenching response when exposed to the 3-NP and 4-NP, the visual detection limits of 0.5 µM and 0.1 µM, respectively. Furthermore, the low toxicity and biocompatibility of CDs were also demonstrated by evaluating in cell culturing experiments, and the CDs showed good potential application in imaging. In summary, the prepared CDs were promising for fluorescent, paper sensors and bioimaging.