Demonstration of a surface plasmon-coupled emission (SPCE)-based immunoassay in the absence of a spacer layer
Demonstration of a surface plasmon-coupled emission (SPCE)-based immunoassay in the absence of a spacer layer
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DOI：
10.1007/s00216-010-4026-8
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发表时间：
2010-11-01
影响因子：
4.3
通讯作者：
MacCraith, Brian D.
中科院分区：
文献类型：
--
作者：
Yuk, Jong Seol;McDonagh, Colette;MacCraith, Brian D.
表面等离子体耦合发射（SPCE）技术涉及将从荧光团发射的光耦合到相邻薄金属膜的表面等离子体中，从而产生高度定向的发射。我们结合了SPCE的优点与超临界角荧光的高光收集效率，通过在没有通常用于最小化荧光的金属淬灭的常规SPCE间隔层的情况下在抛物面阵列生物芯片上进行免疫测定。在这项工作中，我们已经成功地证明了一个基于SPCE的检测，利用蛋白质检测层作为间隔层。使用具有抛物面元件的新型3 × 3注塑成型聚合物生物芯片。抛物面元件用于增强光收集效率，而顶表面涂覆有金层以使用表面等离子体激元的激发和SPCE发射的检测。对金-蛋白质层结构的理论模拟表明，表面等离子体共振角位于抛物面生物芯片的检测范围内。还证明了SPCE发射的偏振依赖性。最后，进行人IgG夹心免疫测定，其使用3 σ表现出类似于10 ng/ml的检测限。结果表明，基于SPCE的抛物面阵列生物芯片作为高通量分析生物分子相互作用的新平台的潜力。
The technique of surface plasmon-coupled emission (SPCE) involves the coupling of light which is emitted from a fluorophore into the surface plasmon of an adjacent thin metal film, giving rise to highly directional emission. We have combined the advantages of SPCE with the high light collection efficiency of supercritical angle fluorescence by carrying out an immunoassay on a paraboloid array biochip in the absence of the conventional SPCE spacer layer normally used to minimize metal quenching of the fluorescence. In this work, we have successfully demonstrated an SPCE-based assay by utilizing the protein assay layer as the spacer layer. A novel 3 x 3 injection molded polymer biochip with paraboloid elements was used. The paraboloid elements served to enhance the light collection efficiency while the top surface was coated with a gold layer to use excitation of surface plasmons and detection of SPCE emission. Theoretical modeling of the gold-protein layer structure showed that the surface plasmon resonance angles were located in the detection range of the paraboloid biochip. The polarization dependence of SPCE emission was also demonstrated. Finally, a human IgG sandwich immunoassay was carried out which exhibited a limit of detection of similar to 10 ng/ml using 3 sigma. The results demonstrate the potential of the SPCE-based paraboloid array biochip as a novel platform for high-throughput analysis of biomolecular interactions.