AbstractThe authors report on an electrochemical immunosensor for the tumor marker carbohydrate antigen 15–3 (CA15–3). It is based on the use of a composite consisting of reduced graphene oxide (RGO) and copper sulfide (CuS) that was placed on a screen-printed graphite electrode. The electrode shows excellent activity towards the oxidation of catechol acting as an electrochemical probe, best at a working potential of 0.16 V. The electrode was modified with antibody against CA15–3. Once the analyte (CA15–3) binds to the surface of the electrode, the response to catechol is reduced. The assay has a linear response in the 1.0–150 U mL−1 CA15–3 concentration range, with a 0.3 U mL−1 lower detection limit and a sensitivity of 1.88 μA μM−1 cm−2. The immunosensor also shows good reproducibility (2.7%), stability (95% of the initial values after storing for four weeks). The method was successfully applied to the determination of CA15–3 in serum samples, and results were found to compare well to those obtained by an ELISA. Conceivably, this nanocomposite based detection scheme has a wider scope and may be applied to numerous other immunoassays. Graphical abstractA label-free electrochemical immunosensor based on copper sulfides/graphene nanocomposites was developed for enzyme-free determination of CA15–3 biomarker. This immunosensor can be utilized as a tool to detect of CA15–3 in real samples.

中文翻译：

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基于CuS/还原氧化石墨烯纳米复合材料对儿茶酚电氧化的催化活性的乳腺癌标志物CA 15-3的电化学免疫传感器

摘要作者报告了一种用于肿瘤标志物碳水化合物抗原 15-3 (CA15-3) 的电化学免疫传感器。它基于使用放置在丝网印刷石墨电极上的由还原氧化石墨烯 (RGO) 和硫化铜 (CuS) 组成的复合材料。该电极作为电化学探针对邻苯二酚的氧化显示出优异的活性，最佳工作电压为 0.16 V。该电极用抗 CA15-3 的抗体进行了修饰。一旦分析物 (CA15-3) 与电极表面结合，对儿茶酚的响应就会降低。该测定在 1.0-150 U mL-1 CA15-3 浓度范围内具有线性响应，检测下限为 0.3 U mL-1，灵敏度为 1.88 μA μM-1 cm-2。免疫传感器还显示出良好的重现性 (2.7%)，稳定性（储存 4 周后初始值的 95%）。该方法已成功应用于血清样品中 CA15-3 的测定，结果与 ELISA 获得的结果具有良好的比较。可以想象，这种基于纳米复合材料的检测方案具有更广泛的范围，可以应用于许多其他免疫测定。图形摘要开发了一种基于硫化铜/石墨烯纳米复合材料的无标记电化学免疫传感器，用于无酶测定 CA15-3 生物标志物。该免疫传感器可用作检测实际样品中 CA15-3 的工具。这种基于纳米复合材料的检测方案具有更广泛的范围，可以应用于许多其他免疫测定。图形摘要开发了一种基于硫化铜/石墨烯纳米复合材料的无标记电化学免疫传感器，用于无酶测定 CA15-3 生物标志物。该免疫传感器可用作检测实际样品中 CA15-3 的工具。这种基于纳米复合材料的检测方案具有更广泛的范围，可以应用于许多其他免疫测定。图形摘要开发了一种基于硫化铜/石墨烯纳米复合材料的无标记电化学免疫传感器，用于无酶测定 CA15-3 生物标志物。该免疫传感器可用作检测实际样品中 CA15-3 的工具。