Here we have reported a simple and sensitive bio-barcode immunosensor for simultaneous detection of 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), 1-aminohydantoin (AHD), and semicarbazide (SEM) in aquatic products. According to freeze–thaw strategy, four fluorophores (FAM, HEX, ROX, Cy5) labeled single-stranded DNA (ssDNA) were conjugated onto the surface of gold nanoparticles (AuNPs) with corresponding four nitrofuran metabolites monoclonal antibodies (mAbs) for forming four bio-barcode fluorescence immunoprobes. The fluorescence of immunoprobes was quenched by AuNPs. In test progress, the ssDNA with fluorophores were released by adding the dithiothreitol (DTT) and the fluorescence recovered. The immunosensor exhibited sensitive and specific detection of nitrofuran metabolites from 0.05 to 28 μg/L. The limit of detection (LOD) was 0.01, 0.02, 0.02, and 0.05 μg/L for AOZ, AMOZ, AHD, and SEM, respectively. The recoveries of four nitrofuran metabolites in spiked aquatic products have been confirmed by UPLC-MS/MS. The bio-barcode based multiplex immunosensor provides a promising strategy for simultaneous detection of multiple targets.

在这里，我们报道了一种简单而灵敏的生物条形码免疫传感器，用于同时检测 3-氨基-2-恶唑烷酮 (AOZ)、3-氨基-5-吗啉代甲基-2-恶唑烷酮 (AMOZ)、1-氨基乙内酰脲 (AHD) 和水产品中的氨基脲 (SEM)。根据冻融策略，将四种荧光团（FAM、HEX、ROX、Cy5）标记的单链 DNA（ssDNA）与相应的四种硝基呋喃代谢物单克隆抗体（mAb）缀合到金纳米颗粒（AuNPs）的表面，形成四种生物条形码荧光免疫探针。免疫探针的荧光被 AuNPs 淬灭。在测试过程中，通过添加二硫苏糖醇（DTT）释放带有荧光团的ssDNA并恢复荧光。免疫传感器对 0.05 至 28 μg/L 的硝基呋喃代谢物表现出灵敏和特异的检测能力。AOZ、AMOZ、AHD 和 SEM 的检测限 (LOD) 分别为 0.01、0.02、0.02 和 0.05 μg/L。UPLC-MS/MS 证实了加标水产品中四种硝基呋喃代谢物的回收率。基于生物条形码的多重免疫传感器为同时检测多个目标提供了一种有前途的策略。