Convenient Determination of Sulfamethazine in Milk by Novel Ratiometric Fluorescence with Carbon and Quantum Dots with On-site Naked-eye Detection and Low Interferences

Sulfamethazine, one of the most widely applied feed additives, has been shown to cause negative health effects to humans. In the present work, a novel and facile fluorescence visual detection probe was established to determine sulfamethazine in milk samples with naked-eye detection. Considering the good stability, excellent optical properties, and easy synthesis, blue-emission carbon dots were used as the standard signal and red-emission CdTe quantum dots as the responsive signal for the determination of sulfamethazine. The fluorescence intensity of red-emission CdTe quantum dots was gradually quenched with increasing concentration of sulfamethazine, while the blue-emission carbon dots response remained constant. Apparent color variations were observed by naked-eye detection in the concentration range from 9.0 to 54 µmol · L−1. In addition, the presented strategy was shown to be promising to provide a rapid, facile, and sensitive method for the determination of sulfamethazine in milk samples with few interferences.