General Surgery Department, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan 030032, China.
Department of Breast Surgery, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan 030032, China.
Molecules. 2022 Oct 11;27(20):6778. doi: 10.3390/molecules27206778.
Convenient and sensitive detection of tumor biomarkers is crucial for the early diagnosis and treatment of cancer. Herein, we present a probe-integrated and label-free electrochemical immunosensor based on binary nanocarbon composites and surface-immobilized methylene blue (MB) redox probes for detection of carbohydrate antigen 199 (CA19-9), which is closely associated with gastric malignancies. Nanocarbon composites consisting of electrochemically reduced graphene oxides and carbon nanotubes (ErGO-CNT) are electrodeposited onto an indium tin oxide (ITO) electrode surface to form a 3D nanocomposite film, which could provide high surface area to immobilize abundant MB probes, facilitate the electron transfer of MB, and therefore, improve sensitivity. Polydopamine (PDA) served as a bifunctional linker is able to immobilize anti-CA19-9 antibodies and stabilize the inner probe, conferring the sensing interface with specific recognition capacity. Electrochemical detection of CA19-9 is achieved based on the decrease of the redox signal of MB after specific binding of CA19-9 with a wide linear range of 0.1 mU/mL to 100 U/mL and a limit of detection (LOD) of 0.54 nU/mL (S/N = 3). The constructed electrochemical immunosensor has good selectivity, repeatability, reproducibility, and stability. Furthermore, determination of CA19-9 in human serum samples is also realized.
方便、灵敏地检测肿瘤标志物对于癌症的早期诊断和治疗至关重要。在此，我们提出了一种基于二元纳米碳复合材料和表面固定亚甲基蓝（MB）氧化还原探针的探针集成和无标记电化学免疫传感器，用于检测与胃恶性肿瘤密切相关的糖类抗原 19-9（CA19-9）。由电化学还原氧化石墨烯和碳纳米管（ErGO-CNT）组成的纳米碳复合材料被电沉积到氧化铟锡（ITO）电极表面上，形成 3D 纳米复合薄膜，该薄膜可以提供高表面积来固定大量的 MB 探针，促进 MB 的电子转移，从而提高了灵敏度。聚多巴胺（PDA）作为一种双功能连接物，能够固定抗 CA19-9 抗体并稳定内探针，赋予传感界面特异性识别能力。CA19-9 的电化学检测是基于 CA19-9 与 MB 特异性结合后 MB 的氧化还原信号降低来实现的，具有 0.1 mU/mL 至 100 U/mL 的宽线性范围和 0.54 nU/mL（S/N = 3）的检测限（LOD）。所构建的电化学免疫传感器具有良好的选择性、重复性、重现性和稳定性。此外，还实现了对人血清样品中 CA19-9 的测定。
