Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, PR China.
Biosens Bioelectron. 2013 Jun 15;44:101-7. doi: 10.1016/j.bios.2013.01.025. Epub 2013 Jan 23.
A multiplex electrochemiluminescence (ECL) immunoassay for simultaneous determination of two different tumor markers, alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), using multicolor quantum dots as labels and graphene as conducting bridge was developed. Herein, a typical sandwich immune complex was constructed on the glass carbon electrode, with QDs525 and QDs625 labeled on secondary anti-AFP and anti-CEA antibodies, respectively, thus to obtain distinguishable ECL signals. Because most of those QDs labeled on secondary antibodies were beyond the space domain of the ECL reaction, graphene was used as a conducting bridge to promote the electron transfer between QDs and the electrode, leading to about 30-fold enhancement of the ECL intensity. Experimental results revealed that the multiplex electrochemiluminescence immunoassay enabled the simultaneous monitoring of AFP and CEA in a single run with a working range of 0.001-0.1 pg/mL. The detection limit (LOD) for both analytes at 0.4 fg/mL was very low. No obvious cross-reactivity was found. Precision, recovery and stability were satisfactory. This novel multiplex ECL immunoassay provided a simple, sensitive, specific and reliable alternative for the simultaneous detection of tumor markers in clinical laboratory.
一种基于多重电化学发光（ECL）免疫分析的方法，用于同时测定两种不同的肿瘤标志物，甲胎蛋白（AFP）和癌胚抗原（CEA），该方法使用多色量子点作为标记物，石墨烯作为导电桥。在此，在玻碳电极上构建了典型的三明治免疫复合物，其中分别用 QD525 和 QD625 标记在二级抗 AFP 和抗 CEA 抗体上，从而获得可区分的 ECL 信号。由于大多数标记在二级抗体上的 QD 超出了 ECL 反应的空间域，因此使用石墨烯作为导电桥来促进 QD 与电极之间的电子转移，从而使 ECL 强度增强约 30 倍。实验结果表明，该多重电化学发光免疫分析能够在单次运行中同时监测 AFP 和 CEA，其工作范围为 0.001-0.1 pg/mL。两种分析物的检测限（LOD）在 0.4 fg/mL 时非常低。未发现明显的交叉反应。精密度、回收率和稳定性均令人满意。这种新型的多重 ECL 免疫分析为临床实验室同时检测肿瘤标志物提供了一种简单、灵敏、特异和可靠的替代方法。
