Multiplexed detection of cancer markers is of great value in clinical diagnosis. Herein, we present a new immunoassay method for simultaneous quantification of multiple tumor biomarkers. Our approach integrates photonic crystals (PhC) barcodes with DNA hybridization chain reaction (HCR) to amplify signal. Target biomarkers are captured by primary antibodies which are immobilized onto the PhC barcodes, forming sandwich immunocomplex with the assistance of second antibodies that are conjugated with DNA initiator. Subsequently, a chain reaction of hybridization events is propagated in attendance of a pair of complementary FAM-decorated H1 and H2 hairpin probes. As a result, the PhC barcodes exhibit multiplex encoding ability for different markers. By utilizing PhC barcodes with HCR for immunoassay, low-abundance cancer biomarkers (CEA, AFP and PSA) can be screened with high detection sensitivity and specificity. Our results showed a wide range from 0.001 to 1000 ng/mL; and the detection limit as low as 0.50 pg/mL. Our approach was also evaluated for analyzing human serum sample with considerable accuracy, which implies its potential as a new platform for simultaneous multiplex immunoassay.

癌症标志物的多重检测在临床诊断中具有重要价值。在这里，我们提出了一种新的免疫测定方法，用于同时量化多种肿瘤生物标志物。我们的方法将光子晶体（PhC）条形码与DNA杂交链反应（HCR）集成在一起以放大信号。靶生物标志物被固定在PhC条形码​​上的一抗捕获，并在与DNA引发剂偶联的二抗的辅助下形成三明治免疫复合物。随后，在一对互补的FAM装饰的H1和H2发夹探针的陪伴下传播了杂交事件的链式反应。结果，PhC条形码​​表现出针对不同标记的多重编码能力。通过使用带有HCR的PhC条形码​​进行免疫分析，低丰度癌症生物标记物（CEA，可以高检测灵敏度和特异性筛选AFP和PSA）。我们的结果显示范围从0.001到1000 ng / mL；检出限低至0.50 pg / mL。我们的方法也被评估用于以相当高的准确性分析人血清样品，这暗示了它作为同时进行多重免疫测定的新平台的潜力。