Carcinoembryonic antigen (CEA) is considered as a disease biomarker, which is related to various cancers and tumors in the human bodies. Sensitive detection of CEA is significant for clinical diagnosis and treatment. Herein, we proposed an electrochemical aptasensor for CEA detection based on the amplification driven by polydopamine functional graphene and Pd-Pt nanodendrites (PDA@Gr/Pd-PtNDs), conjugated hemin/G-quadruplex (hemin/G4), which possess mimicking peroxidases activity. Firstly, PDA@Gr was modified on the electrode surface for fixing CEA aptamer 1 (Apt1). Then, PDA@Gr/Pd-PtNDs with large surface area served as matrix for immobilization of hemin/G4 to obtain the secondary aptamer. In virtue of the sandwich-type specific reaction between CEA and the corresponding aptamers, the second aptamer was captured on the sensing interface, which can catalyze the oxidation of signal probe hydroquinone (HQ) with H₂O₂ and amplify current signal. Furthermore, the electrochemical signals of HQ were proportional with CEA concentrations. Under the optimal conditions, a dynamic response range from 50 pg/mL to 1.0 μg/mL and a detection limit of 6.3 pg/mL for CEA were obtained. Moreover, the proposed strategy represented satisfactory sensitivity and stability, and showed a good precision in real samples application.

癌胚抗原（CEA）被认为是一种疾病的生物标志物，与人体内的各种癌症和肿瘤有关。CEA的灵敏检测对于临床诊断和治疗具有重要意义。在此，我们提出了一种用于 CEA 检测的电化学适体传感器，该传感器基于由具有模拟过氧化物酶的多巴胺功能石墨烯和 Pd-Pt 纳米树突 (PDA@Gr/Pd-PtNDs)、共轭 hemin/G-四链体 (hemin/G4) 驱动的放大。活动。首先，PDA@Gr 在电极表面进行修饰，用于固定 CEA 适体 1 (Apt1)。然后，以大比表面积的PDA@Gr/Pd-PtNDs为基质，固定hemin/G4，得到二级适体。凭借 CEA 与相应适体之间的三明治型特异性反应，第二个适体被捕获在传感界面上，₂ O ₂并放大电流信号。此外，HQ 的电化学信号与 CEA 浓度成正比。在最佳条件下，CEA的动态响应范围为50 pg/mL至1.0 μg/mL，检测限为6.3 pg/mL。此外，所提出的策略具有令人满意的灵敏度和稳定性，在实际样品应用中表现出良好的精度。