Abstract: Fluorescent carbon dots could be prepared by using pre-carbonized Chinese fir powder as the carbon source though the oxidation method. The obtained carbon dots were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectroscopy. The results showed that the carbon dots were spherical with the particle size of 1-8 nm, the surface of carbon dots had carboxyl, hydroxy and amino and so on, and the carbon dots had good water solubility and anti-salt property; the carbon dots emitted strong blue fluorescence with the maximum emission wavelength of 455 nm under the excitation band of 335 nm and the quantum yield was 8.3%. The intensity of the fluorescence was sensitive to the pH value. Based on the quenching effect of nitrofurazone on the fluorescence of carbon dots, the quenching experiment was conducted with different concentrations of nitrofurazone. As a result, a sensitive approach was developed for the detection of nitrofurazone in the range of 0.2-100 μmol/L with the detection limit of 70 nmol/L based on the fluorescence resonance energy transfer (FRET) and inner filter effect (IFE) between carbon dots and nitrofurazone with the linear equation of F₀/F=0.965+0.015c and linear correlation coefficient of 0.994 6.

Key words: Chinese fir powder, nitrofurazone, carbon dots, fluorescence