Signal-on fluorescent sensor based on N-CQDs for the detection of glutathione in human serum and pharmaceutic preparation.

Nitrogen-doped carbon quantum dots (N-CQDs) with citric acid and ethylenediamine as raw materials were synthesized by an efficient one-step strategy. The N-CQDs showed a special property that the fluorescence was quenched by Fe3+. The quenched fluorescence of N-CQDs could be recovered by glutathione (GSH). Therefore, a "signal-on" fluorescent sensor was developed to detect GSH. The fluorescent sensor could favorably avoid the interference of ascorbic acid, dopamine, glucose, oxidized glutathione, and other amino acids in the detecting process of GSH. The proposed sensor showed a great feature that GSH can be accurately detected in the range from 0.001 to 0.1 mol/L and can be applied to detect GSH in the human serum. Therefore, the proposed method has a promising application for monitoring the blood drug concentration of GSH in clinical studies.