Bimetallic PtAg nanowires (PtAgNWs) were synthesized through a water-based mild chemical route for the first time. Due to their high conductivity, large surface area, and synergistic electronic effects of the alloyed Pt–Ag atoms, the obtained catalysts exhibited considerably high oxygen reduction activities. This unique catalytic property along with desired functionalities and surface charge characteristics provide interesting platforms for interfacing signal amplification. A novel label-free electrochemical immunosensor for ultrasensitive detection of alpha-fetoprotein (AFP) was then developed based on bimetallic PtAgNW catalyzed oxygen reduction for signal amplification. Under optimal conditions, the amperometric signal decreases linearly with AFP concentration (0.001–36 ng mL⁻¹), resulting in a low limit of detection (0.2 pg mL⁻¹). Satisfactory results were demonstrated concerning the application of the novel immunosensor for the detection of AFP in real samples.

中文翻译：

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PtAg纳米线：简便的合成及其作为无标记电化学免疫分析的优异氧还原电催化剂的应用

首次通过水基温和化学路线合成了双金属PtAg纳米线（PtAgNWs）。由于它们的高电导率，较大的表面积以及合金化的Pt-Ag原子的协同电子效应，所获得的催化剂表现出相当高的氧还原活性。这种独特的催化性能以及所需的功能和表面电荷特性为接口信号放大提供了有趣的平台。然后，基于双金属PtAgNW催化的氧还原，开发了一种用于超灵敏检测甲胎蛋白（AFP）的新型无标记电化学免疫传感器，用于信号放大。在最佳条件下，安培信号随AFP浓度（0.001–36 ng mL ^-1），导致检出限低（0.2 pg mL ^-1）。关于新型免疫传感器在实际样品中检测AFP的应用，结果令人满意。