Fluorescence “turn-on” Sensing Platform for Glutathione Detection Using Chitosan-Based Glutaraldehyde Non-conjugated Polymers

We established a fluorescence “turn-on” sensing platform for glutathione (GSH) detection utilizing chitosan-based glutaraldehyde non-conjugated polymers (GCPF) as nanomaterials via fluorescence resonance energy transfer (FRET) principle. Owing to the overlapping property of absorption spectrum of MnO2 nanosheets with fluorescence spectrum of GCPF, fluorescent intensity of GCPF was quenched in the presence of MnO2 nanosheets because of FRET principle. When GSH was added, MnO2 nanosheets were reduced and decomposed into large amounts of Mn2+ ions owing to reducing property of GSH. Accordingly, the quenched fluorescent intensity was turned on again. Therefore, this platform based on MnO2 nanosheet has been first applied to fluorescence “turn-on” detection of GSH from 0.5 to 50 μmol/L with sdetection limit of 84 nmol/L. It showed high selectivity in GSH detection towards other ions and biomolecules such as L-lysine, L-threonine, L-valine, L-glutamic acid and DL-aspartic acid. When it was utilized in detecting GSH in serum samples, satisfactory recoveries ranged from 101.5% to 103.2%, indicating the accuracy of this fluorescence “turn-on” platform in bioanalysis.