Background: The electrochemical sensors convert biological or chemical information, such as analyte concentration or a biomolecular (biochemical receptor) interaction, into electrical signals. In this paper, we describe the development of a poly-thionine/ single-walled carbon nanotube (P-Th/SWCNT) composite for the electrochemical detection of ascorbic acid (vitamin C). Methods: To improve electrochemical performance, we attempted to electro-polymerize the thionine monomers, an essential chemical building block, directly on the surface of singlewalled carbon nanotubes (SWCNT). Results: Field Emission Scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) results revealed that a complex structure of the P-Th/SWCNT was formed. The presence of carbon (C), oxygen (O), nitrogen (N), and sulfur (S) components was confirmed, which indicated the effective fusion of poly-thionine onto SWCNT. Moreover, the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed the composite formation. Utilizing cyclic voltammetry, the composite's electrochemical behavior was examined. Conclusions: Excellent electrocatalytic activity towards the oxidation of ascorbic acid was shown by the P-Th/SWCNT composite. The as-prepared P-Th/SWCNT composite-modified sensor can detect ascorbic acid in food, medical, and pharmaceutical samples.

中文翻译：

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用于测定维生素 C 的聚硫堇/单壁碳纳米管纳米复合涂层电化学传感器

背景：电化学传感器将生物或化学信息（例如分析物浓度或生物分子（生化受体）相互作用）转换为电信号。在本文中，我们描述了用于电化学检测抗坏血酸（维生素C）的聚硫堇/单壁碳纳米管（P-Th/SWCNT）复合材料的开发。方法：为了提高电化学性能，我们尝试直接在单壁碳纳米管（SWCNT）的表面上电聚合硫堇单体（一种重要的化学构件）。结果：场发射扫描电子显微镜（FESEM）和能量色散光谱（EDS）结果表明形成了 P-Th/SWCNT 的复杂结构。证实了碳（C）、氧（O）、氮（N）和硫（S）成分的存在，这表明聚硫堇有效地融合到SWCNT上。此外，X射线衍射（XRD）和傅里叶变换红外（FTIR）光谱证实了复合材料的形成。利用循环伏安法检查了复合材料的电化学行为。结论：P-Th/SWCNT 复合材料对抗坏血酸氧化表现出优异的电催化活性。所制备的P-Th/SWCNT复合修饰传感器可以检测食品、医疗和药品样品中的抗坏血酸。