Neuroendocrine tumors (NETs) are rare heterogeneous tumors that are often misdiagnosed and mistreated. Most NETs patients are diagnosed as advanced. Early on-time detection of NETs is significant for precision therapy. Here, an ultrasensitive and antifouling label-free electrochemical immunosensor was constructed for simultaneous analysis of NETs biomarkers chromogranin A (CgA) and chromogranin B (CgB). The metal ion functionalized porous magnesium silicate/gold nanoparticles/polyethylene glycol/chitosan (PMS-M²⁺/AuNPs/PEG/CS) composites were employed as the sensing platforms. By combining PEG and CS with good hydrophilicity, the sensing interface exhibited outstanding antifouling ability in complex biological systems. PMS with high surface area and the porous structure can efficiently load Cu²⁺ and Pb²⁺, which could directly generate independent electrochemical peak currents that reflected the concentrations of CgA and CgB. Under optimal conditions, this immunosensor can detect CgA and CgB with good linearity from 0.1 pg mL⁻¹ to 100 ng mL⁻¹ as low as 5.3 and 2.1 fg mL⁻¹, respectively. Moreover, this immunosensor can accurately detect CgA and CgB levels in clinical serum, which were well consistent with the enzyme-linked immunosorbent assay (ELISA). This strategy provided a sensitive, simple and low-cost platform for clinical screening and point-of-care diagnosis of NETs.

神经内分泌肿瘤（NETs）是一种罕见的异质性肿瘤，经常被误诊和误治。大多数 NET 患者被诊断为晚期。NETs 的早期准时检测对于精准治疗具有重要意义。在这里，构建了一种超灵敏和防污无标记的电化学免疫传感器，用于同时分析 NET 生物标志物嗜铬粒蛋白 A (CgA) 和嗜铬粒蛋白 B (CgB)。采用金属离子功能化多孔硅酸镁/金纳米粒子/聚乙二醇/壳聚糖（PMS-M ²⁺ /AuNPs/PEG/CS）复合材料作为传感平台。通过结合具有良好亲水性的PEG和CS，传感界面在复杂的生物系统中表现出出色的防污能力。具有高表面积和多孔结构的 PMS 可有效负载 Cu ²⁺和 Pb ²⁺，可以直接产生独立的电化学峰值电流，反映 CgA 和 CgB 的浓度。在最佳条件下，该免疫传感器可以检测 CgA 和 CgB，线性度从 0.1 pg mL ^-1到 100 ng mL ^{-1 分别}低至 5.3 和 2.1 fg mL ^-1。此外，该免疫传感器可以准确检测临床血清中的 CgA 和 CgB 水平，这与酶联免疫吸附试验 (ELISA) 非常一致。该策略为 NET 的临床筛查和即时诊断提供了一个敏感、简单和低成本的平台。