19-nortestosterone (19-NT), being regarded as the residual marker of banned synthetic steroid hormone nandrolone phenylpropionate, could cause adverse effects when consumed by human. To ensure food safety and minimize 19-NT toxicity, herein, an innovative electrochemical immunosensor for detection of 19-NT was constructed based on the modified polyvinyl alcohol/polyacrylic acid (PVA/PAA) nanofiber mat (NFM). The detection was achieved via a direct competition for binding to horse radish peroxidase-tagged anti-19-NT nanobody between free 19-NT and the 19-NT-ovalbumin covalently immobilized onto the NFM, and the amperometric response of immunosensor was analyzed using cyclic voltammetry. Under the optimal preparation conditions, the PVA/PAA NFM with appropriate hydrophilicity and ultra-high surface was obtained and characterized, and its electrochemical performance exhibited a 20-times increased response compared to the PVA/PAA casting membrane. The established immunosensor possessed high sensitivity towards 19-NT with a detection limit of 2.14 pg/mL, a 46-fold times lower compared to the traditional ic-ELISA of pure anti-19-NT nanobody. Recovery rates from the spiked animal urine samples ranged from 97.09 % to 117.32 %. Moreover, the sensor showed good reproducibility and stability over 6 weeks, suggesting that the nanofiber-based biosensor is a promising alternative for the fast and sensitive determination of 19-NT.

19-去甲睾酮（19-NT）被认为是禁用合成类固醇激素苯丙酸诺龙的残留标志物，被人类食用后可能会产生不良影响。为了确保食品安全并最大限度地减少 19-NT 毒性，本文基于改性聚乙烯醇/聚丙烯酸 (PVA/PAA) 纳米纤维垫 (NFM) 构建了一种用于检测 19-NT 的创新电化学免疫传感器。该检测是通过游离19-NT和共价固定在NFM上的19-NT-卵白蛋白之间与辣根过氧化物酶标记的抗19-NT纳米抗体的直接竞争结合来实现的，并使用循环分析免疫传感器的电流响应。伏安法。在最佳制备条件下，获得了具有适当亲水性和超高比表面积的 PVA/PAA NFM，并对其进行了表征，与 PVA/PAA 流延膜相比，其电化学性能表现出 20 倍的响应。建立的免疫传感器对 19-NT 具有高灵敏度，检测限为 2.14 pg/mL，与传统的纯抗 19-NT 纳米抗体 ic-ELISA 相比低 46 倍。加标动物尿液样品的回收率范围为 97.09 % 至 117.32 %。此外，该传感器在 6 周内表现出良好的重现性和稳定性，表明基于纳米纤维的生物传感器是快速、灵敏地测定 19-NT 的有希望的替代品。与纯抗 19-NT 纳米抗体的传统 ic-ELISA 相比，降低了 46 倍。加标动物尿液样品的回收率范围为 97.09 % 至 117.32 %。此外，该传感器在 6 周内表现出良好的重现性和稳定性，表明基于纳米纤维的生物传感器是快速、灵敏地测定 19-NT 的有希望的替代品。与纯抗 19-NT 纳米抗体的传统 ic-ELISA 相比，降低了 46 倍。加标动物尿液样品的回收率范围为 97.09 % 至 117.32 %。此外，该传感器在 6 周内表现出良好的重现性和稳定性，表明基于纳米纤维的生物传感器是快速、灵敏地测定 19-NT 的有希望的替代品。