Mahmoud Ashraf M, Alqarni Ali O, Ali Ramadan, El-Wekil Mohamed M
Department of Pharmaceutical Chemistry, College of Pharmacy, Najran University, Najran, Saudi Arabia.
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt.
Anal Methods. 2025 Jan 2;17(2):360-367. doi: 10.1039/d4ay01839g.
Accurate determination of glutathione (GSH) in food supplements and human biological fluids is critical for preventing disorders related to GSH imbalances. To address this, a selective and sensitive fluorometric method was developed for GSH detection using nickel nanoclusters functionalized with polyvinylpyrrolidone (PVP) and 4-mercaptobenzoic acid (4-MBA) (PVP/4-MBA@Ni NCs). In this system, PVP serves as the stabilizer, while 4-MBA functions as both a stabilizer and reducing agent. In the presence of Fe ions, the fluorescence response of the PVP/4-MBA@Ni NCs decreased due to aggregation and the inner-filter effect. Upon the addition of GSH, a bithiol compound that chelates Fe ions, the fluorescence emission was restored. This recovery occurred due to the formation of a stable chelate between GSH and Fe ions. The fluorescence intensity ratios (/) increased linearly with GSH concentration in the range of 0.018-50 μM, with a detection limit (LOD, S/N = 3 : 1) of 0.005 μM. The PVP/4-MBA@Ni NCs/Fe system offers several advantages, including rapid detection time, high selectivity, and a low detection limit. This system was successfully applied to detect GSH in real-world samples such as dietary supplement capsules and human biological fluids, showing good recovery percentages and low relative standard deviation (RSD) values. These results confirm the reliability of the fluorescent system for detecting GSH in various samples.
准确测定食品补充剂和人体生物体液中的谷胱甘肽（GSH）对于预防与GSH失衡相关的疾病至关重要。为了解决这个问题，开发了一种选择性和灵敏的荧光法，使用聚乙烯吡咯烷酮（PVP）和4-巯基苯甲酸（4-MBA）功能化的镍纳米簇（PVP/4-MBA@Ni NCs）检测GSH。在该体系中，PVP作为稳定剂，而4-MBA既作为稳定剂又作为还原剂。在铁离子存在下，由于聚集和内滤效应，PVP/4-MBA@Ni NCs的荧光响应降低。加入GSH（一种螯合铁离子的二硫醇化合物）后，荧光发射恢复。这种恢复是由于GSH与铁离子形成了稳定的螯合物。荧光强度比（/）在0.018 - 50 μM的GSH浓度范围内与GSH浓度呈线性增加，检测限（LOD，S/N = 3∶1）为0.005 μM。PVP/4-MBA@Ni NCs/Fe体系具有几个优点，包括检测时间短、选择性高和检测限低。该体系已成功应用于检测膳食补充剂胶囊和人体生物体液等实际样品中的GSH，回收率良好，相对标准偏差（RSD）值较低。这些结果证实了该荧光体系在检测各种样品中GSH方面的可靠性。
