The sensitive and accurate identification of interleukin-6 (IL-6) in biological fluids is essential for assessing migraine due to its role in different physiological and pathological processes. In this study, we designed a simple and feasible electrochemical immunosensing method for the voltammetric measurement of IL-6. The electrochemical immunosensor was fabricated through covalent conjugation of anti-IL-6 capture antibodies on the glassy carbon electrode with a typical carbodiimide coupling method. Anti-IL-6 secondary antibodies were labeled on the surface of Prussian blue-doped CaCO₃ nanoparticles (PBCaNP) via the epoxy-amino reaction. The assay was carried out with a sandwich-type immunoreaction. In the presence of target IL-6, the analyte was sandwiched between the capture antibody and detection antibody. Thereafter, the carried PBCaNP accompanying the secondary antibody could be detected by using square wave voltammetry (SWV). The voltammetric peak current was dependent on the concentration of target IL-6. Under optimum conditions, the electrochemical immunosensor exhibited good analytical properties, and allowed detection of IL-6 within a wide linear range from 0.1 to 1000 pg mL⁻¹. The limit of detection was estimated to be 0.078 pg mL⁻¹ of IL-6 at the 3s_B criterion. An intermediate reproducibility of ≤10.59% was accomplished with batch-to-batch identification, and good anti-interference capacity against other biomolecules was achieved. Importantly, clinical human serum samples obtained from 15 migraine patients were analyzed with the developed electrochemical immunosensors, giving results well-matched with those obtained from the referenced enzyme-linked immunosorbent assay (ELISA) method.

中文翻译：

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普鲁士蓝掺杂 CaCO3 纳米颗粒标记的二抗用于偏头痛患者白细胞介素 6 的电化学免疫测定


由于其在不同生理和病理过程中的作用，生物体液中白细胞介素 6 （IL-6） 的灵敏准确鉴定对于评估偏头痛至关重要。在这项研究中，我们设计了一种简单可行的电化学免疫传感方法用于 IL-6 的伏安法测量。电化学免疫传感器是通过在玻碳电极上用典型的碳二亚胺偶联方法对抗 IL-6 捕获抗体共价偶联来制造的。通过环氧-氨基反应在普鲁士蓝掺杂 CaCO₃ 纳米颗粒 （PBCaNP） 的表面标记抗 IL-6 二抗。该测定采用夹心型免疫反应进行。在存在靶标 IL-6 的情况下，分析物夹在捕获抗体和检测抗体之间。此后，可以使用方波伏安法 （SWV） 检测二抗附带的 PBCaNP。伏安峰值电流取决于目标 IL-6 的浓度。在最佳条件下，电化学免疫传感器表现出良好的分析特性，并允许在 0.1 至 1000 pg ^mL-1 的宽线性范围内检测 IL-6。在 3s_B 标准下，检测限估计为 0.078 pg ^mL-1 的 IL-6。通过批次间鉴定实现了 ≤10.59% 的中等重现性，并且对其他生物分子具有良好的抗干扰能力。 重要的是，使用开发的电化学免疫传感器分析了从 15 名偏头痛患者获得的临床人体血清样本，得出的结果与从参考的酶联免疫吸附测定 （ELISA） 方法获得的结果非常匹配。