Abstract This study represents a label-free immunoassay for carcinoembryonic antigen (CEA) by microfluidic biosensor based on imaging ellipsometry (BIE) and its application is further validated by clinic sera. The sandwich format of analysis configuration was adopted, in which Rat-mAb was served as capture antibody, rabbit anti-CEA polyclonal antibody (rabbit-pAb) as detection antibody and goat anti-rabbit IgG (goat-IgG) as an enhancer added to increase detection signal. The methodology includes rat-mAb concentration screening, rabbit-pAb and goat-IgG concentration optimization, creation of dose-response curve and determination of cutoff value. Results show the linear range is from 4.0–64.0 ng/ml with a lower limit of 1.0 ng/ml (S/N = 3). Application of the BIE to clinic samples demonstrated that the relation coefficient is 0.94 and substantial agreement with the results of ECLIA’s (Kappa = 0.733, U = 4.35 > U0.01). The proposed method exhibits the potential for application.

中文翻译：

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基于成像椭偏仪的微流控生物传感器对癌胚抗原的无标记免疫分析及其临床应用

摘要 本研究代表了一种基于成像椭圆光度法 (BIE) 的微流控生物传感器对癌胚抗原 (CEA) 进行无标记免疫测定，其应用得到了临床血清的进一步验证。采用夹心形式的分析配置，其中Rat-mAb作为捕获抗体，兔抗CEA多克隆抗体（rabbit-pAb）作为检测抗体，山羊抗兔IgG（goat-IgG）作为增强剂加入增加检测信号。该方法包括大鼠 mAb 浓度筛选、兔 pAb 和山羊 IgG 浓度优化、剂量反应曲线的创建和截断值的确定。结果显示线性范围为 4.0–64.0 ng/ml，下限为 1.0 ng/ml (S/N = 3)。将 BIE 应用于临床样本表明相关系数为 0。94 并且与 ECLIA 的结果基本一致（Kappa = 0.733，U = 4.35 > U0.01）。所提出的方法展示了应用的潜力。