Lung cancer is a high-mortality cancer related to the concentration of neuron-specific enolase (NSE). In this work, a sandwich-type photoelectrochemical (PEC) immunosensor was constructed for ultrasensitive detection of NSE, which is based on iron trioxide/indium zinc cadmium sulfide (Fe₂O₃/Cd-ZnIn_2.2S_y) as a sensing platform and Ag-modified polyaniline (Ag@PANI) as a signal amplification label. The 1D Fe₂O₃ porous nanorods with a large specific surface area were synthesized by calcination of Fe-MIL-88A and etching of NaOH. To improve the photocurrent response, the 3D architecture Cd-ZnIn_2.2S_y was combined with the 1D Fe₂O₃ porous nanorods to form a 1D Fe₂O₃/3D Cd-ZnIn_2.2S_y heterostructure. Specifically, the Fe₂O₃/Cd-ZnIn_2.2S_y heterostructure with a good energy level matching (the two can form a stepped energy level matching, which accelerates the transfer rate of electrons) can improve the separation efficiency of electron–hole pairs (e^–/h⁺) under visible light irradiation, which enhances the photocurrent response. Ag@PANI has a strong electron transport capability and can be used as a secondary antibody marker for the signal amplification of the immunosensor. The sensor exhibits a good linear detection range of 100 fg/mL to 100 ng/mL with a low detection limit of 33.5 fg/mL. Moreover, the constructed sandwich-type PEC immunosensor shows good performance and possesses excellent specificity, selectivity, and stability over a period of 4 weeks for NSE detection. With these excellent properties, the immunosensor can be extended to analyze and diagnose other disease biomarkers.

中文翻译：

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基于一维 Fe2O3/3D Cd-ZnIn2.2Sy 异质结构的光电化学免疫传感器作为超灵敏检测神经元特异性烯醇化酶的传感平台

肺癌是一种高死亡率癌症，与神经元特异性烯醇化酶 (NSE) 的浓度有关。在这项工作中，基于三氧化二铁/铟锌硫化镉（Fe ₂ O ₃ /Cd-ZnIn _2.2 S _y）作为传感平台和Ag 修饰的聚苯胺 (Ag@PANI) 作为信号放大标记。通过Fe-MIL-88A的煅烧和NaOH的刻蚀，合成了具有大比表面积的一维Fe ₂ O _{3多孔纳米棒。}为了改善光电流响应，将 3D 结构 Cd-ZnIn _2.2 S _y与 1D Fe 相结合₂ O ₃多孔纳米棒形成一维Fe ₂ O ₃ /3D Cd-ZnIn _2.2 S _y异质结构。具体来说，具有良好能级匹配的Fe ₂ O ₃ /Cd-ZnIn _2.2 S _y异质结构（两者可以形成阶梯式能级匹配，加速电子的传输速率）可以提高电子-空穴对的分离效率(e ^– /h ⁺) 在可见光照射下，增强了光电流响应。Ag@PANI具有很强的电子传输能力，可作为免疫传感器信号放大的二抗标记。该传感器具有 100 fg/mL 至 100 ng/mL 的良好线性检测范围，检测下限为 33.5 fg/mL。此外，所构建的夹心型PEC免疫传感器在NSE检测中表现出良好的性能，在4周内具有优异的特异性、选择性和稳定性。凭借这些优异的特性，免疫传感器可以扩展到分析和诊断其他疾病生物标志物。