Detection of oxytetracycline in milk using a novel carbon dots-based fluorescence probe via facile pyrolysis synthesis.

Abstract

Amphiphilic blue-fluorescence carbon dots (B-CDs) were synthesized via pyrolysis method with citric acid and oleamine as precursors. B-CDs are monodispersed in ethanol, toluene, and ultrapure water with the average particle sizes of 3.33nm, 2.05nm, and 4.12nm, respectively. The maximum emission wavelength of the B-CDs excitation at 370nm is located at 459nm. The B-CDs have good optical properties with excellent photostability. The fluorescence quantum yield (QY) of the as-prepared CDs is as high as 30.17%. The fluorescence of B-CDs is quenched because of static quenching by oxytetracycline. A high selective and sensitive fluorescence probe for detecting oxytetracycline was constructed with a linear range of 1.52-27.60µg/mL and the detection limit of 0.33µg/mL. The B-CDs-based fluorescence probe can be applied to analyze oxytetracycline in milk; the recoveries and relative standard are satisfactory. Furthermore, the B-CDs were exploited for imaging of SH-SY5Y cells. The results demonstrate that as-synthesized CDs can serve as a cellular imaging reagent owing to remarkable bioimaging performance. This work provides a new strategy for the detection of oxytetracycline in food.