Abstract

To accurately detect tumor marker carbohydrate antigen 72-4 (CA72-4) of serum samples is of great significance for the early diagnosis of malignant tumors. In the present study, MnO₂/hollow nanobox metal-organic framework (HNM)-AuPtPd nanocomposites were prepared via multi-step synthesis and superposition method and a series of characterizations were carried out. A highly sensitive immunosensor Ab/MnO₂/HNM-AuPtPd/GCE based on the composite nanomaterial was further prepared and used to detect the tumor marker CA72-4. The constructed immunosensor achieved signal amplification by increasing the electrocatalytic activity to H₂O₂ by means of the synergistic effect of MnO₂ ultra-thin nanosheets (MnO₂ UNs) and HNM-AuPtPd. At the same time, the electrochemical properties of the immunosensor were analyzed using cyclic voltammetry, electrochemical impedance, amperometry (with the test voltage of −0.4 V), and differential pulse voltammetry. The experimental results showed that the MnO₂/HNM-AuPtPd nanocomposites were successfully prepared, and the immunosensor Ab/MnO₂/HNM-AuPtPd/GCE demonstrated an excellent electrochemical performance. The electrochemical immunosensor had the highest detection sensitivity under the optimal experimental conditions, such as incubation pH of 7.0, incubation time of 60 min, with the addition of 15 μL of H₂O₂, and in the concentration range 0.001–500 U/mL. It had a low detection limit of 1.78×10⁻⁵ U/mL (S/N = 3). Moreover, the serum sample recovery were in the range from 99.38 to 100.52%. This study provides a new method and experimental basis for the detection of tumor markers in clinical practice.

Graphical Abstract

中文翻译：

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基于MnO2纳米片和HNM-AuPtPd纳米复合材料的电化学免疫传感器检测肿瘤标志物CA72-4

摘要

准确检测血清样本中的肿瘤标志物糖抗原72-4（CA72-4）对于恶性肿瘤的早期诊断具有重要意义。本研究通过多步合成和叠加方法制备了MnO ₂ /空心纳米盒金属有机骨架(HNM)-AuPtPd纳米复合材料，并进行了一系列表征。进一步制备了基于复合纳米材料的高灵敏免疫传感器Ab/MnO ₂ /HNM-AuPtPd/GCE，并用于检测肿瘤标志物CA72-4。构建的免疫传感器通过MnO ₂超薄纳米片(MnO ₂ UNs)和HNM-AuPtPd的协同作用，提高对H ₂ O ₂的电催化活性，实现信号放大。同时，利用循环伏安法、电化学阻抗、电流分析法（测试电压-0.4 V）和微分脉冲伏安法对免疫传感器的电化学性能进行了分析。实验结果表明，成功制备了MnO ₂ /HNM-AuPtPd纳米复合材料，免疫传感器Ab/MnO ₂ /HNM-AuPtPd/GCE表现出优异的电化学性能。在最佳实验条件下，如孵育pH为7.0、孵育时间为60 min、加入15 μL H ₂ O ₂、浓度范围为0.001~500 U/mL，电化学免疫传感器具有最高的检测灵敏度。 。其检测限较低，为1.78×10 ^-5 U/mL (S/N = 3)。此外，血清样品回收率在99.38%至100.52%之间。该研究为临床肿瘤标志物的检测提供了新的方法和实验基础。

图形概要