A Self-Assembly Fluorescence Sensing Platform for Glutathione Detection Based on Eco-Friendly Quantum Dots and MnO2 Nanosheets

Glutathione (GSH), a thiol-containing tripeptide, has a pivotal role in maintaining the normally physiological environment in biology. Here, we report a novel self-assembly fluorescence resonance energy transfer (FRET) sensing platform for GSH detection by using the environment-friendly Cu:Zn–In–S/ZnS quantum dots (QDs) and MnO2 nanosheets. In this assay, fluorescence of Cu:Zn– In–S/ZnS QDs could be quenched by MnO2 nanosheets based on FRET. Upon the addition of GSH, MnO2 nanosheets were reduced into Mn2+ ions because of the rapid redox reaction, and consequently the fluorescence of QDs was recovered. A good linear relationship was obtained from 1 to 20 μM for the detection of GSH with a low detection limit of 500 nM. Meanwhile, the sensing system also exhibited high selectivity against other electrolytes and biomolecules. Moreover, the satisfactory results in the determination of GSH in serum samples indicate that the assay holds great potential for detecting GSH in biological fluids. This method shows many advantages including high sensitivity, short assay time, good simplicity as well as label-free and environmental friendly, which is expected to facilitate the GSH quantification relating to biological and biomedical studies.