Abstract Polycrystalline cerium oxide thin films (15 nm) deposited on a glassy carbon substrate were used as an electrode in a mediator-free, non-enzymatic electrochemical sensor for hydrogen peroxide. The electrode surface was characterized by X-ray photoelectron spectroscopy, resonant photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. The electrode sensitivity, detection limit and pH range of sensor stability were determined by applying electrochemical techniques: cyclic voltammetry and chronoamperometry. It was found that the sensor reactivity to H2O2 is directly related to the presence of electroactive cerium centres of 3+ character on the electrode surface. The Michaelis–Menten mechanism of catalase-like activity of ceria film is suggested as an explanation of the data and discussed. The results confirmed the sensing abilities of technologically well-accessible nanostructured cerium oxide films for hydrogen peroxide detection without using a mediator, i.e. the enzymatic properties of CeO2/GC electrode.

中文翻译：

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用于检测过氧化氢的多晶氧化铈薄膜的电化学活性

摘要 沉积在玻璃碳基底上的多晶氧化铈薄膜 (15 nm) 被用作无介体、非酶促过氧化氢电化学传感器中的电极。通过X射线光电子能谱、共振光电子能谱、扫描电子显微镜和原子力显微镜对电极表面进行表征。通过应用电化学技术：循环伏安法和计时电流法来确定电极灵敏度、​​检测极限和传感器稳定性的 pH 范围。发现传感器对 H2O2 的反应性与电极表面上 3+ 字符的电活性铈中心的存在直接相关。提出了二氧化铈薄膜过氧化氢酶样活性的 Michaelis-Menten 机制作为对数据的解释和讨论。