This work reports the development of an electrochemical immunosensor for rapid, specific and decentralized detection of the invasion-associated protein p60 secreted by Listeria monocytogenes, a life-threatening foodborne pathogen. A disposable screen-printed electrode was used as transducer surface and monoclonal and polyclonal antibodies that specifically recognize Listeria monocytogenes p60 protein and Listeria spp. p60 proteins, respectively, were used as the sandwich immuno-pair. The reaction was detected with the aid of an additional secondary antibody conjugated with the enzyme reporter (alkaline phosphatase) and a 3-indoxyl phosphate/silver ions as the mixture substrate. The analytical signal was acquired through the voltammetric stripping of the enzymatically deposited silver, which was directly correlated to p60 concentration in the sample. In optimized conditions, a limit of detection and quantification of 1.5 ng mL⁻¹ and 5.1 ng mL⁻¹ were achieved, respectively, in a useful time (<3 h). As proof-of-concept, the proposed immunosensor was successfully applied to spiked milk samples, demonstrating to be a suitable device for further use in real sample detection of Listeria monocytogenes in food products.

这项工作报告了一种电化学免疫传感器的开发，该传感器可用于快速，特异性和分散性检测单核细胞增生性李斯特菌（一种威胁生命的食源性病原体）分泌的入侵相关蛋白p60 。一次性丝网印刷电极用作换能器表面，以及特异性识别单核细胞增生性李斯特菌p60蛋白和李斯特菌的单克隆和多克隆抗体spp。p60蛋白分别用作三明治免疫对。借助于与酶报告物（碱性磷酸酶）缀合的另外的第二抗体和作为混合物底物的3-吲哚磷酸/银离子检测反应。分析信号通过酶解沉积的银的伏安汽提获得，这与样品中的p60浓度直接相关。在优化的条件下，在有效时间内（<3小时），检测和定量限分别达到1.5 ng mL ^-1和5.1 ng mL ^-1。作为概念验证，所提出的免疫传感器已成功应用于加标牛奶样品，证明是进一步用于实际样品检测的合适设备。食品中的单核细胞增生李斯特菌。