In this paper, we developed a sensitive sensor for phytic acid (PA) and hydrogen peroxide (H2O2) detection based on glutathione-functionalized graphene quantum dots (GQDs@GSH). The fluorescence of GQDs@GSH was found to be effectively quenched by Fe3+ ions via photo-induced electron transfer (PET) process. Upon the addition of PA to GQDs@GSH/Fe3+ system, the fluorescence of GQDs@GSH was significantly restored due to the strong chelating and reducing ability of PA, Fe3+ ions could be reduced to Fe2+ ions by PA and formed PA/Fe2+ complex. Therefore, the "off-on" fluorescence method was constructed to detect PA by using GQDs@GSH/Fe3+ as a fluorescent probe. Furthermore, the method can be used for the detection of H2O2. H2O2 can destroy the chelate structure of PA/Fe2+, release Fe2+ ions and oxidize Fe2+ ions to produce Fe3+ ions, leading to the fluorescence quenching of GQDs@GSH again. Under optimal conditions, the fluorescence sensing platform showed good linear relationship between the relative fluorescence intensity I/I0 and the concentration of PA and H2O2 in the range of 0.05-3 μmol L-1 and 0.5-10 μmol L-1, respectively. The detection limits of PA and H2O2 were 14 nmol L-1 and 0.134 μmol L-1, respectively. Furthermore, the fluorescence assay method was also applied in real sample analysis and satisfactory results were obtained.

中文翻译：

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一种用于高灵敏度检测植酸和过氧化氢的新型荧光传感策略

在本文中，我们开发了一种基于谷胱甘肽功能化石墨烯量子点 (GQDs@GSH) 的用于植酸 (PA) 和过氧化氢 (H2O2) 检测的灵敏传感器。发现 GQDs@GSH 的荧光可通过光诱导电子转移 (PET) 过程被 Fe3+ 离子有效淬灭。在 GQDs@GSH/Fe3+ 体系中加入 PA 后，由于 PA 的强螯合和还原能力，GQDs@GSH 的荧光显着恢复，Fe3+ 离子可以被 PA 还原为 Fe2+ 离子并形成 PA/Fe2+ 络合物。因此，构建了以GQDs@GSH/Fe3+为荧光探针的“off-on”荧光法检测PA。此外，该方法可用于检测 H2O2。H2O2可以破坏PA/Fe2+的螯合结构，释放Fe2+离子，氧化Fe2+离子产生Fe3+离子，再次导致 GQDs@GSH 的荧光猝灭。在最佳条件下，荧光传感平台的相对荧光强度I/I0与PA和H2O2浓度分别在0.05-3 μmol L-1和0.5-10 μmol L-1范围内表现出良好的线性关系。PA 和 H2O2 的检测限分别为 14 nmol L-1 和 0.134 μmol L-1。此外，该荧光测定法也应用于实际样品分析，并获得了满意的结果。PA 和 H2O2 的检测限分别为 14 nmol L-1 和 0.134 μmol L-1。此外，该荧光检测方法也应用于实际样品分析，并获得了满意的结果。PA 和 H2O2 的检测限分别为 14 nmol L-1 和 0.134 μmol L-1。此外，该荧光测定法也应用于实际样品分析，并获得了满意的结果。