Liu Xiaojun, Sun Yuanyuan, Lin Xinyi, Pan Xiaoyan, Wu Zhangjian, Gai Hongwei
School of Chemistry and Materials Science, Jiangsu Normal University, 101 Shanghai Road, Tongshan District, Xuzhou 221116, Jiangsu, China.
School of Medicine, The Second Affiliated Hospital of Zhejiang University, 88 Jiefang Road, Shangcheng District, Hangzhou 310009, Zhejiang, China.
Anal Chem. 2021 Feb 16;93(6):3089-3095. doi: 10.1021/acs.analchem.0c04020. Epub 2021 Feb 4.
Digital multiplexed homogeneous immunoassay is supposed to have the advantages of high sensitivity, high analytical throughput, small sampling errors, and low consumption. We present a spectral imaging-based multiplex, homogenous immunoassay by counting sandwich-structured immunocomplexes in the form of quantum dot (QD) aggregates. As a proof of concept, the method was utilized to detect two tumor biomarkers: carcino-embryonic antigen (CEA) and α-fetoprotein (AFP). The immunocomplex induced by CEA contained QD 655 and QD 585 and were recognized by the spectral pattern of dual-color QD aggregates under a transmission-grating-based spectral imaging microscope. Immunocomplexes induced by AFP were labeled with the QD 585 aggregate and were identified by the spectral blue-shift pattern of same-color QD aggregates. Limits of detection for AFP and CEA were calculated to be 0.02 and 0.10 pM at a signal-to-noise ratio of 3, respectively. Further successful quantification of the model proteins in human plasma demonstrated the accuracy and reliability of our approach.
数字多路复用均相免疫测定法具有高灵敏度、高分析通量、小采样误差和低消耗等优点。我们提出了一种基于光谱成像的多路复用均相免疫测定法，通过对量子点（QD）聚集体形式的夹心结构免疫复合物进行计数来实现。作为概念验证，该方法被用于检测两种肿瘤生物标志物：癌胚抗原（CEA）和甲胎蛋白（AFP）。CEA诱导的免疫复合物包含QD 655和QD 585，并在基于透射光栅的光谱成像显微镜下通过双色QD聚集体的光谱模式进行识别。AFP诱导的免疫复合物用QD 585聚集体标记，并通过同色QD聚集体的光谱蓝移模式进行鉴定。在信噪比为3时，AFP和CEA的检测限分别计算为0.02和0.10 pM。进一步成功地对人血浆中的模型蛋白进行定量，证明了我们方法的准确性和可靠性。
