Carbon dot-based fluorescent sensor for selective and sensitive detection of persulfate†

Persulfate, a powerful oxidizing agent, is extensively employed in numerous industries. Accurate and rapid detection of persulfate (S₂O₈²⁻) is essential. This study reports the development of a fluorescent sensor based on Am-CDs. It is synthesized from ascorbic acid (AA) and m-phenylenediamine (m-PD) through a one-step hydrothermal method. The fluorescence of Am-CDs demonstrated selective sensitivity to S₂O₈²⁻ via static quenching. A sensitive fluorescent sensor was constructed for S₂O₈²⁻, exhibiting a linear detection range of 1.96 to 15.59 μM with a limit of detection (LOD) of 0.94 μM. This fluorescence method was successfully applied to detect S₂O₈²⁻ in water samples, achieving recoveries of 98.07% to 102.33%. The fluorescent sensor developed in this study offers a simple and effective method for quantifying S₂O₈²⁻ in aquatic environments.