An ultrasensitive electrochemical immunosensor was fabricated by employing reduced graphene oxide-thionin-hemin-Au (H-rGO-Thi-Au) nanohybrid as probe to measure neuron specific enolase (NSE), a lung cancer biomarker. In this work, the reduced graphene oxide (rGO) was used as support material to immobilize hemin and thionin through aromatic π-π interaction. Then Au nanoparticles were reduced by thionin in situ on the probe. The immunoprobe offers several advantages as follows: (1) thionin can be enriched for signal amplification; (2) the catalysis ability of hemin can be enhanced by preventing the molecules aggregation; (3) the reduced graphene oxide-hemin (H-rGO) acts as signal amplifier to accelerate the redox cycling with H₂O₂; (4) the composite with good conductivity is beneficial to improve response current. Apart from that, polyaniline hydrogel as substrate prepared by electrochemical polymerization on the glassy carbon electrode showed excellent conductivity which can further improve the performance of immunosensor. Thus, the proposed immunosensor showed excellent analytical performance for the detection of NSE with wide linear range from 0.1 pg mL⁻¹ to 100 ng mL⁻¹ and low detection limit of 0.026 pg mL⁻¹. It is also of note that human serum samples were determined with satisfactory results, indicating its value on clinical application.

一种超灵敏的电化学免疫传感器是通过使用还原型氧化石墨烯-硫蛋白-血红素-Au（H-rGO-Thi-Au）纳米杂交体作为探针来测量神经元特异性烯醇化酶（NSE）（一种肺癌生物标记物）而制成的。在这项工作中，还原的氧化石墨烯（rGO）被用作载体材料，以通过芳香族π-π相互作用固定血红素和硫蛋白。然后，在探针上通过硫蛋白原位还原金纳米颗粒。免疫探针具有以下几个优点：（1）硫蛋白可以被富集用于信号放大；（2）通过防止分子聚集可以增强血红素的催化能力；（3）还原的氧化石墨烯-血红素（H-rGO）充当信号放大器，以加速H ₂ O ₂的氧化还原循环; （4）具有良好导电性的复合材料有利于提高响应电流。除此之外，在玻璃碳电极上通过电化学聚合制备的聚苯胺水凝胶作为基质表现出优异的电导率，可以进一步提高免疫传感器的性能。因此，所提出免疫表现出优良的分析性能用于检测NSE的宽线性范围为0.1皮克毫升^-1至100ng毫升^-1和0.026微克毫升低检测限^-1。还值得注意的是，人血清样品的测定结果令人满意，表明其在临床应用中的价值。