本研究构建了一种电化学免疫传感器，用于检测人体血清中的细胞角蛋白19片段抗原21-1（CYFRA 21-1）。CYFRA 21-1是非小细胞肺癌（NSCLC）最敏感的肿瘤标志物，正常人血清中的含量应不超过3.3 ng/mL。当肺癌细胞溶解或死亡时，大量的CYFRA 21-1释放到肿瘤患者的血液循环中，其血清含量显著升高。因此，通过电化学生物传感器检测CYFRA 21-1有望提供一种早期检测和预防肺癌的新方法。本研究使用UiO-66-NH2和羧基化多壁碳纳米管（CMWCNTs）的复合材料作为传感器的基底材料；所得传感器具有较大的比表面积和良好的电导性。此外，金纳米颗粒（AuNPs）通过Au-S键与抗体结合。通过特异性的抗原和抗体结合，实现了CYFRA 21-1的超灵敏检测。在最佳检测条件下，免疫传感器电流信号强度的变化与CYFRA 21-1浓度的对数成比例，并在0.005-400 ng/mL的范围内呈线性关系，检测限为1.15 pg/mL（S/N = 3）。所提出的免疫传感器具有高精确性，稳定性和选择性。更重要的是，该传感器成功应用于人体血清中CYFRA 21-1的检测，具有较高的回收率，为肺癌的早期筛查和动态监测提供了一种新方法。版权所有©2023 Elsevier B.V.发表。

In this study, an electrochemical immunosensor was constructed to detect the cytokeratin 19 fragment antigen 21-1 (CYFRA 21-1) in human serum. CYFRA 21-1 is the most sensitive tumor marker of non-small cell lung cancer (NSCLC), its content in normal human serum should be less than 3.3 ng/mL. When lung cancer cells dissolve or die, a myriad of CYFRA 21-1 is released into a tumor patient's blood circulation, and its serum content elevates strikingly. Consequently, detecting CYFRA 21-1 by an electrochemical biosensor is expected to provide a new method for the early detection and prevention of lung cancer. In this study, a composite of UiO-66-NH2 and carboxylated multi-walled carbon nanotubes (CMWCNTs) was used as the substrate material of a sensor; the resulting sensor had a large specific surface area and strong electrical conductivity. Moreover, gold nanoparticles (AuNPs) were used to bind to antibodies through an Au-S bonds. Also, a supersensitive detection of CYFRA 21-1 was achieved through the specific bindings of antigens and antibodies. Under optimal detection conditions, the change of current signal intensity of the immunosensor was proportional to the logarithm of CYFRA 21-1 concentration and had a linear relation in the range of 0.005-400 ng/mL, while the detection limit was 1.15 pg/mL (S/N = 3). The proposed immunosensor had high precision, stability, and selectivity. More importantly, the sensor was been successfully applied to detect CYFRA 21-1 in human serum with high recovery, providing a new method for early screening and dynamic monitoring of lung cancer.Copyright © 2023. Published by Elsevier B.V.