Carbon dots-based fluorescence method for determination of oxytetracycline in wastewater, milk, and meat samples.

Water-soluble and highly yellow fluorescent carbon dots were synthesized by using sucrose as a carbon source and phosphoric acid as a dehydrating agent. Instrumental techniques such as fourier transform infrared spectroscopy, ultraviolet absorption and fluorescence spectroscopy, and transmission electron microscopy have been employed to characterize the carbon dots. The results indicated that the synthesized carbon dots have spherical shape with mean diameter of 7 nm. The distribution of carbon dots is uniform which emit yellow fluorescence. Fourier transform infrared spectroscopy study revealed the presence of high amount of –OH groups on carbon dots surface. Oxytetracycline quenched the fluorescence of carbon dots via static quenching mechanism. The reduction in fluorescence intensity of carbon dots permitted to design a fluorometric assay for oxytetracycline. The calibration curve (change in fluorescence intensity vs. concentration of oxytetracycline) was linear in the concentration range of 1.0 μg/mL–10.0 μg/mL with a detection limit of 0.33 μg/mL and correlation coefficient of 0.9981. The method was tested to quantify the oxytetracycline in spiked wastewater, milk, and meat samples and gave satisfactory recoveries. [ABSTRACT FROM AUTHOR]