A novel L‐cysteine (CysH) electrochemical sensor based on CeO₂ nanofibers (NFs) modified screen printed carbon electrodes (SPCEs) was developed. The morphology and the structure of the as‐prepared CeO₂ NFs were first characterized using scanning electron microscopy (SEM) and X‐ray diffraction pattern (XRD), respectively. The electrochemical and electrocatalytic performances of the CeO₂ NFs modified SPCEs were then evaluated using cyclic voltammetry and amperometry. Experimental results showed that the CeO₂ NFs modified SPCEs possess excellent electrocatalytic activity toward the detection of CysH. Specifically, the developed electrochemical sensor demonstrated a high sensitivity of 120 μA mM⁻¹ cm⁻², a low detection limit of 20 nM (signal to noise ratio of 3) and a wide linear range up to 200 μM for the determination of CysH, which are among the best values reported in literature. In addition, good selectivity and outstanding intra‐ and inter‐electrode reproducibility have also been observed. Furthermore, the developed CysH sensor was applied to detect CysH spiked into human serum samples with remarkable accuracy. All these features indicate that CeO₂ NFs hold great promise in the development of high performance electrochemical sensor for CysH.

中文翻译：

---

基于氧化铈纳米纤维修饰的丝网印刷碳电极的灵敏和选择性电化学测定半胱氨酸

开发了一种基于CeO ₂纳米纤维（NFs）修饰的丝网印刷碳电极（SPCE）的新型L-半胱氨酸（CysH）电化学传感器。首先分别使用扫描电子显微镜（SEM）和X射线衍射图谱（XRD）对所制备的CeO ₂ NF的形态和结构进行了表征。然后使用循环伏安法和安培法评估CeO ₂ NFs修饰的SPCE的电化学和电催化性能。实验结果表明，CeO ₂ NFs修饰的SPCE对CysH的检测具有优异的电催化活性。具体而言，已开发的电化学传感器显示出120μAmM ^-1  cm的高灵敏度^-2，检测CysH的低检测限为20 nM（信噪比为3），线性范围高达200μM，是文献报道的最佳值。此外，还观察到良好的选择性和极好的电极内和电极间重现性。此外，已开发的CysH传感器被用于检测掺入人血清样品中的CysH，具有显着的准确性。所有这些特征表明，CeO ₂ NFs在开发用于CysH的高性能电化学传感器方面具有广阔的前景。