In this paper, Cu-doped carbon quantum dots (Cu-CQDs) were prepared by carrying out thermolysis of Na 2 [Cu(EDTA)] and hydroxylamine hydrochloride at 300 °C for 2 h. The asprepared Cu-CQDs were characterized by UV-Vis, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The Cu-CQDs exhibited good fluorescence property, high stability, excitationdependent emission behavior and a quantum yield of 9.8%. More significantly, the synthesized Cu-CQDs were developed for sensing rutin (RT) based on the fluorescence quenching of the prepared Cu-CQDs. A good linear relationship between the fluorescence quenching of Cu-CQDs and different concentrations of RT was obtained in the range of 0.1-15 μg mL -1 with a correlation coefficient of 0.9959. The detection limit was as low as 0.05 μg mL -1 (signal-to-noise ratio, S/N = 3). The possible mechanism of fluorescence quenching was explored, which was proved to be inner filter effect. Importantly, the proposed method was successfully applied in the detection of RT tablet samples and with satisfactory results, showing the practical applications.Keywords: Cu-doped carbon quantum dots, rutin, Na 2 [Cu(EDTA)], fluorescence sensors Rutin tablet samples pretreatment 10 pieces of rutin tablets were ground to powder in a mortar, and 10 mg of the powder was dissolved in 25 mL of ethanol. Recovery experiments were performed by adding different concentrations of rutin to the treated samples.
Results and Discussion
Characterization of Cu-CQDsThe optical properties of the Cu-CQD were investigated by UV-Vis absorption and fluorescence emission spectra. The UV-Vis spectrum (Figure 2a) showed two shoulders at Fluorescent Sensors Based on Cu-Doped Carbon Quantum Dots for the Detection of Rutin J. Braz. Chem. Soc. 990