Monitoring endogenous glutathione (GSH) levels in living cells is essential for cancer diagnose and treatment. In this work, GSH responsive fluorescent nanoprobe with turn-on property was constructed using Zn-modified porphyrinic metal-organic frameworks (PCN-224-Zn). The introduced Zn²⁺ could quench the fluorescence of PCN-224 by the metallization of organic ligand (TCPP) and serves as sensing site for GSH. When exposed to GSH, the strong binding affinity of GSH generates the formation of Zn-GSH complex, eliminating the fluorescence quenching effect of Zn²⁺. Based on the constructed PCN-224-Zn nanoprobe, selective determination of GSH was achieved in the range of 0.01–6 μM with a detection limit of 1.5 nM. Furthermore, the constructed nanoprobe can realize the fluorescence imaging of endogenous GSH in MCF-7 and HeLa cells. Meanwhile, PCN-224-Zn could also monitor GSH in cell lysate with recovery rates from 93.8 % to 102.3 %. The performance of PCN-224-Zn demonstrates its capacities in the application of fluorescence sensing and bio-imaging fields.

监测活细胞中的内源性谷胱甘肽 (GSH) 水平对于癌症诊断和治疗至关重要。在这项工作中，利用锌修饰的卟啉金属有机框架（PCN-224-Zn）构建了具有开启特性的GSH响应荧光纳米探针。引入的Zn ²⁺可以通过有机配体(TCPP)的金属化来猝灭PCN-224的荧光，并作为GSH的传感位点。当暴露于GSH时，GSH的强结合亲和力生成Zn-GSH复合物的形成，消除了Zn ²⁺的荧光猝灭效应。基于构建的PCN-224-Zn纳米探针，实现了GSH在0.01~6 μM范围内的选择性测定，检测限为1.5 nM。此外，构建的纳米探针可以实现MCF-7和HeLa细胞中内源性GSH的荧光成像。同时，PCN-224-Zn还可以监测细胞裂解液中的GSH，回收率从93.8%到102.3%。 PCN-224-Zn的性能证明了其在荧光传感和生物成像领域的应用能力。