Key Laboratory of Biomedical Functional Materials, School of Sciences, China Pharmaceutical University, Nanjing 211198, China; Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA.
Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
Anal Chim Acta. 2018 Aug 17;1019:103-110. doi: 10.1016/j.aca.2018.02.048. Epub 2018 Feb 21.
As a new class of l-cysteine electrocatalyst explored in this study, Au/CeO composite nanofibers (CNFs) were employed to modify the screen printed carbon electrode (SPCE) to fabricate a novel l-cysteine (CySH) electrochemical sensor with high performance. Its electrochemical behavior and the roles of Au and CeO in the composite toward electro-oxidation of CySH were elucidated and demonstrated using cyclic voltammetry and amperometry techniques for the first time through the comparison with pure CeO NFs. More specifically, the Au/CeO CNFs modified SPCE possessed greatly enhanced electrocatalytic activity toward CySH oxidation. An ultra high sensitivity of 321 μA mMcm was obtained, which is almost 2.7 times higher than that of pure CeO NFs, revealing that the presence of Au imposed an important influence on the electrocatalytic activity toward CySH. The detailed reasons on such high performance were also discussed. In addition, the as-prepared sensor showed a low detection limit of 10 nM (signal to noise ratio of 3), a wide linear range up to 200 μM for the determination of CySH, an outstanding reproducibility and good long-term stability, as well as an excellent selectivity against common interferents such as tryptophan, tyrosine, methionine, ascorbic acid and uric acid. All these features indicate that the Au/CeO composite nanofiber is a promising candidate as a new class of l-cysteine electrocatalyst in the development of highly sensitive and selective CySH electrochemical sensor.
作为本研究探索的一种新型 l-半胱氨酸电催化剂，Au/CeO 复合纳米纤维（CNFs）被用于修饰丝网印刷碳电极（SPCE），以制备一种新型 l-半胱氨酸（CySH）电化学传感器，具有高性能。通过与纯 CeO NFs 的比较，首次使用循环伏安法和安培法技术阐明并证明了 Au 和 CeO 在复合材料中对 CySH 电氧化的作用和作用。更具体地说，Au/CeO CNFs 修饰的 SPCE 对 CySH 氧化具有大大增强的电催化活性。获得了超高的灵敏度 321μA mMcm，几乎是纯 CeO NFs 的 2.7 倍，表明 Au 的存在对 CySH 的电催化活性产生了重要影响。还讨论了这种高性能的详细原因。此外，所制备的传感器对 CySH 的检测限低至 10 nM（信噪比为 3），线性范围宽达 200 μM，具有出色的重现性和良好的长期稳定性，以及对色氨酸、酪氨酸、蛋氨酸、抗坏血酸和尿酸等常见干扰物的优异选择性。所有这些特征表明，Au/CeO 复合纳米纤维是一种很有前途的 l-半胱氨酸电催化剂，可用于开发高灵敏度和选择性的 CySH 电化学传感器。
