Facile and green synthesis of fluorescent carbon dots from the flowers of Abelmoschus manihot (Linn.) Medicus for sensitive detection of 2,4,6-trinitrophenol and cellular imaging

Abstract

A new type of carbon dots (CDs) was synthesized via a one-pot hydrothermal method by using the flowers of Abelmoschus manihot (Linn.) Medicus as precursors for the first time. The CDs exhibited strong blue emission with a fluorescence quantum yield (QY) of 30.8%. Further, the fluorescence intensity of CDs was found to be rapidly and sensitively quenched by 2,4,6-trinitrophenol (TNP), an environmental pollutant. The linear response of TNP ranged from 25 nM to 40 μM with a limit of detection (LOD) of 5 nM. Moreover, the fluorescence quenching effect of TNP on CDs was much higher than those for other competitive compounds and metal ions. The results demonstrated that CDs had high selectivity to TNP. Furthermore, the CDs were successfully applied for the determination of TNP in tap water and river water with the recoveries ranging from 92.6% to 113% (RSD < 5%). These results demonstrated that the CDs can be applied to the selective and sensitive detection of TNP in real samples. Finally, the CDs were explored for cytotoxicity in three cell lines and cellular imaging in Hela cells. Benefited from the good biocompatibility and negligible cytotoxicity, the CDs had great potential for the application in biological field.