A novel ultrasensitive and label-free electrochemical immunosensor was developed and used in combination with electrochemical impedance spectroscopy (EIS) or square wave voltammetry (SWV) for okadaic acid (OA) detection. The prepared immunosensor is primarily composed of polythionine-modified three-dimensional gold nanoelectrode ensembles (3DGNEEs). These ensembles were fabricated by combining electroless and electrochemical deposition. The deposition potential and time of the electrodeposition were optimized to enhance the properties of the 3DGNEEs. OA antibodies (anti-OA) were fixed on the PTh-modified ensembles by glutaraldehyde (GA). The fabrication process of immunosensor was characterized by EIS. The EIS responses were simulated using a newly constructed model of the recognition interface, and the detection limit of SWV is lower than that of EIS (3.20 × 10⁻¹⁵ vs. 2.65 × 10⁻¹² g mL⁻¹), and the linear OA detection range of the former is wider (1 × 10⁻¹²–1 × 10⁻⁷ vs. 5 × 10⁻¹²–1 × 10⁻⁹ g mL⁻¹).

中文翻译：

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基于聚蛋氨酸修饰的三维金纳米电极组的冈田酸超灵敏无标记电化学免疫传感器的开发与建模

开发了一种新型的超灵敏，无标记的电化学免疫传感器，并将其与电化学阻抗谱（EIS）或方波伏安法（SWV）组合用于冈田酸（OA）检测。制备的免疫传感器主要由聚蛋氨酸修饰的三维金纳米电极组件（3DGNEE）组成。通过将化学沉积和电化学沉积相结合来制造这些整体。优化了电沉积的沉积电位和时间，以增强3DGNEE的性能。OA抗体（抗OA）通过戊二醛（GA）固定在PTh修饰的集合上。通过EIS对免疫传感器的制备过程进行了表征。使用新构建的识别界面模型对EIS响应进行了仿真，^-15与2.65×10 ^-12 克毫升^-1），且前者的线性OA检测范围较宽（1×10 ^-12 -1×10 ^-7与5×10 ^-12 -1×10 ^{- 9}  g mL ^-1）。