Jafari Somayeh, Pourmortazavi Seied Mahdi, Ehsani Ali, Mirsadeghi Somayeh
Faculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology, Tehran, Iran.
Department of Chemistry, Faculty of Science, University of Qom, Qom, Iran.
Sci Rep. 2024 Aug 16;14(1):18961. doi: 10.1038/s41598-024-69869-4.
This work has applied metal-organic frameworks (MOFs) with high adsorbability and catalytic activity to develop electrochemical sensors to determine free chlorine (free-Cl) concentrations in aqueous media. A zeolitic imidazolate frameworks, Zn(Hmim) (ZIF-8) has been synthesized and incorporated with CuO nanosheets to decorate a glassy carbon electrode (GCE) and provide a new sensor for free-Cl determination. The as-prepared ZIF-8 and CuO-ZIF-8 composites have been characterized by FESEM, EDX, XRD, and FT-IR analyses. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) utilized to characterize the CuO-ZIF-8/GC modified electrode electrochemically, demonstrated the ability of the sensor to measure free-Cl concentration. Using differential pulse voltammetry (DPV) and under the optimal conditions, the prepared CuO-ZIF-8/GC modified electrode showed a linear response in the 0.25-60 ppm range with a 12 ppb detection limit (LOD) for free-Cl concentration. Finally, the fabricated sensor was applied to analyze free-Cl from actual swimming pool water samples with promising 97.5 to 103.0% recoveries.
这项工作应用了具有高吸附性和催化活性的金属有机框架（MOF）来开发电化学传感器，以测定水介质中的游离氯（游离-Cl）浓度。合成了一种沸石咪唑酯框架Zn(Hmim)（ZIF-8），并将其与CuO纳米片结合，修饰玻碳电极（GCE），从而提供一种用于测定游离-Cl的新型传感器。通过场发射扫描电子显微镜（FESEM）、能谱仪（EDX）、X射线衍射仪（XRD）和傅里叶变换红外光谱仪（FT-IR）分析对所制备的ZIF-8和CuO-ZIF-8复合材料进行了表征。利用循环伏安法（CV）和电化学阻抗谱（EIS）对CuO-ZIF-8/GC修饰电极进行电化学表征，证明了该传感器具有测量游离-Cl浓度的能力。在最佳条件下，采用差分脉冲伏安法（DPV），所制备的CuO-ZIF-8/GC修饰电极在0.25-60 ppm范围内呈现线性响应，游离-Cl浓度的检测限（LOD）为12 ppb。最后，将所制备的传感器应用于分析实际游泳池水样中的游离-Cl，回收率在97.5%至103.0%之间，结果令人满意。
