Fluorescence sensing analysis for rapid detection of serum glutathione based on degrading AuNCs@Lys-MnO2 fluorescence resonance energy transfer system

In this work, a gold nanocluster with lysine (Lys) as a ligand was fabricated, and a novel nanocomposite probe (AuNCs@Lys-MnO 2 ) was prepared based on fluorescence resonance energy transfer (FRET). AuNCs@Lys-MnO 2 was manufactured for sensitive and rapid sensing of glutathione (GSH) in human serum. Gold nanoclusters (AuNCs@Lys) and manganese dioxide nanosheets (MnO 2 nanosheets) are combined by electrostatic interaction. MnO 2 nanosheets can quickly quench the fluorescence of AuNCs@Lys through FRET. GSH has strong reducing ability, which can reduce MnO 2 and degrade AuNCs@Lys-MnO 2 FRET system. The presence of GSH subsequently releases AuNCs@Lys, which causes partial recovery of fluorescent signal. The nanocomposite probe is successfully applied to detect GSH in human serum. Detection range is near the normal value in human serum, and there is no need to dilute the serum during the detection process. This is a fast, simple, and cost-effective strategy. The method can detect GSH in the concentration range of 0.5 to 1000 μM, and has a very high sensitivity, the detection limit is as low as 5 nM.