A sensitive full-automated micromagnetic particles (MMPs) based competitive chemiluminescent immunoassay (CLIA) was developed to detect cortisol in milk. Polyclonal antibody (pAb) with good specificity against cortisol was produced. The antigen (cortisol-OVA) was labeled with acridinium ester (cortisol-OVA-AE) as signal tracer. During the detection, the free cortisol in sample will compete with cortisol-OVA-AE for binding to pAb. To capture pAb, MMPs conjugated with goat anti-rabbit IgG was added. The whole immunoassay process (exclude sample pretreatment) was performed by automatic chemiluminescence immunoassay instrument, which could consume less test time (within 40 min) and avoid error from manual operation. The method showed a good detection limit of 0.12 ng/mL, a broad linear range from 0.42 to 72.27 ng/mL for cortisol detection, negligible cross-reactivity with related analogues and satisfied recovery (84.3%-102.3%) for spiked milk samples test. Simultaneously, since the results of proposed method had no significant difference with those of LC-MS/MS, the proposed method was confirmed to have a potential applicability for rapidly monitoring cortisol in the food.

中文翻译：

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基于磁性粒子的全自动化学发光免疫分析法快速检测牛奶中的皮质醇

开发了一种基于竞争性化学发光免疫分析 (CLIA) 的灵敏全自动微磁颗粒 (MMP) 来检测牛奶中的皮质醇。产生了对皮质醇具有良好特异性的多克隆抗体 (pAb)。抗原（皮质醇-OVA）用吖啶酯（皮质醇-OVA-AE）作为信号示踪剂标记。在检测过程中，样品中的游离皮质醇会与皮质醇-OVA-AE 竞争与 pAb 的结合。为了捕获 pAb，添加了与山羊抗兔 IgG 结合的 MMP。整个免疫分析过程（不包括样品前处理）由全自动化学发光免疫分析仪完​​成，测试时间短（40分钟以内），避免人工操作错误。该方法显示出良好的检测限为 0.12 ng/mL，皮质醇检测的线性范围为 0.42 至 72.27 ng/mL，对于加标牛奶样品测试，与相关类似物的交叉反应性可忽略不计，回收率令人满意 (84.3%-102.3%)。同时，由于所提出方法的结果与LC-MS/MS的结果没有显着差异，因此证实所提出的方法具有快速监测食品中皮质醇的潜在适用性。