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 MnO 2 nanosheets with fluorescence spectrum of GCPF, fluorescent intensity of GCPF was quenched in the presence of MnO 2 nanosheets because of FRET principle. When GSH was added, MnO 2 nanosheets were reduced and decomposed into large amounts of Mn 2+ ions owing to reducing property of GSH. Accordingly, the quenched fluorescent intensity was turned on again. Therefore, this platform based on MnO 2 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.