Facile Synthesis of Biomass N, S-CDs for Fluorescent Detection of Tetracycline in Wastewater

As the growing presence of antibiotic residues in environmental water bodies poses an increasing risk to ecological safety and human health, developing simple and efficient methods for the targeted detection of antibiotics is of particular importance. In this study, we propose a simple method for the one-step hydrothermal synthesis of N, S-co-doped carbon dots (N, S-CDs) using disulfide bonds from discarded badminton shuttlecocks. We investigated the effects of different synthesis temperatures on its performance and confirmed the method’s excellent performance in detecting tetracycline (TC) concentrations, with results demonstrating that varying synthesis temperatures affect the degree and distribution of carbonization, thereby influencing fluorescence intensity. Consequently, employing N, S-CDs-180, which exhibits optimal photoluminescence properties, as the sensing probe for the detection of TC solutions at varying concentrations yielded an excellent linear equation for fluorescence quenching and the detection limit is 1.963 mg/L. Additionally, the fluorescence stability of N,S-CDs-180 was investigated in laboratory water, tap water, seawater, lake water, and industrial wastewater, all of which demonstrated exceptional environmental adaptability. Furthermore, a systematic investigation into the target selectivity of N, S-CDs-180 toward various antibiotics revealed that this material exhibits a sensitive quenching response specifically to tetracycline-class antibiotics while showing no quenching effect on non-tetracycline antibiotics, collectively indicating that the as-prepared N, S-CDs can serve as potential fluorescent probes for the highly selective detection of tetracycline-class antibiotics in complex aqueous systems.