Sensitive determination of kaempferol using carbon dots as a fluorescence probe

In this study, a new sensitive and convenient method for the determination of kaempferol (Kae) based on the fluorescence quenching of fluorescent carbon dots (C-dots) was developed. The C-dots were prepared by simply mixing acetic acid, water and diphosphorus pentoxide. This green synthesis approach proceeds rapidly and gives large quantities of C-dots. The fluorescence of the C-dots decreased obviously with the increase of Kae concentration. The effect of other interfering substances on the fluorescence intensity of C-dots showed low interference. Under the optimum conditions, a linear correlation was established between fluorescence intensity ratio Fo/F and the concentration of Kae in the range of 3.5-49 µM with a detection limit (S/N=3) of 38.4 nM. The proposed method has been successfully applied to determination of Kae in xindakang tablets and human serum samples with recovery in the range of 94.6-109.0%. The C-dots could be a promising fluorescence probe for the detection of Kae owing to its low-cost production, easy operation, low cytotoxicity, and excellent biocompatibility.