Fluorescence Determination of Glutathione Using Tissue Paper-derived Carbon Dots as Fluorophores

Glutathione is an important antioxidant found in body fluids and tissues, which inhibit damage to essential cellular constituents caused by reactive oxygen species. The analysis of glutathione levels in biological systems is important in early clinical diagnosis. A novel, cost-effective synthetic strategy has been developed for the fluorescent probe ethylenediamine passivated carbon dots. Tissue paper was chosen as the carbon source for this "green one pot" synthesis. Glutathione could induce quenching of the fluorescence intensity of ethylenediamine passivated carbon dots through surface interactions, resulting from their aggregation. Based on this, a novel fluorescence sensor was fabricated for the determination of Glutathione in body fluids. A linear calibration graph was obtained in the range of 6.0 × 10^-7 to 5.0 × 10^-8 M with a detection limit of 1.74 × 10^-9 M. The developed sensor was successfully used for the determination of glutathione in artificial saliva samples.