Department of Chemical and Biological Engineering, College of Engineering, Korea University, Anam-Ro 145, Seoul 136-713, Republic of Korea.
Nanoscale. 2017 Nov 2;9(42):16476-16484. doi: 10.1039/c7nr03453a.
Current immunoassays are in general performed through time-consuming multi-step procedures that depend on the use of premade signal-producing reporters and often cause assay inaccuracy. Here we report an advanced immunoassay technology that resolves the delayed, complex, and inaccurate assay problems of conventional immunoassays. We have developed an accurate, rapid, simple, and label-free one-step-immunoassay based on the self-enhancement of sensitive immunoassay signals in an assay solution. The nano-scale protein particles (hepatitis B virus capsid and human ferritin heavy chain particles) were genetically engineered to present many well-oriented antibody (or antigen) probes and multi-copies of poly-histidine peptides on their surface, resulting in the construction of 3-dimensional (3D) bioprobes that chemisorb gold ions via coordination bonding and sensitively detect both antigen and antibody analytes. Systematic numerical and experimental analyses show that the signal self-enhancement happens through two coupled reactions under reducing conditions: (1) 3D bioprobe-based sensitive immuno-detection of analytes and (2) coordinated assembly of free and chemisorbed gold nanoparticles around the 3D bioprobe-analyte-associated complexes, which is followed by the quick generation of apparent optical signals. This advanced one-step-immunoassay was successfully applied to diagnostic assays requiring high accuracy and/or speed, i.e. diagnosis of acute myocardial infarction and hepatitis C through detecting a cardiac protein (troponin I) and anti-hepatitis C virus antibodies in patient sera, indicating that it is applicable to the accurate and rapid detection of both antigen and antibody markers of a wide range of diseases.
目前的免疫分析通常通过耗时的多步程序进行，这些程序依赖于使用预制的信号产生报告器，并且常常导致分析不准确。在这里，我们报告了一种先进的免疫分析技术，该技术解决了传统免疫分析中延迟、复杂和不准确的分析问题。我们已经开发了一种准确、快速、简单且无需标记的一步式免疫分析，该分析基于在分析溶液中敏感免疫分析信号的自我增强。纳米级蛋白质颗粒（乙型肝炎病毒衣壳和人铁蛋白重链颗粒）经过基因工程改造，在其表面呈现许多定向良好的抗体（或抗原）探针和多拷贝聚组氨酸肽，从而构建了 3 维（3D）生物探针，这些探针通过配位键化学吸附金离子，并通过化学吸附金离子来灵敏地检测抗原和抗体分析物。系统的数值和实验分析表明，信号自增强是通过还原条件下的两个偶联反应发生的：（1）基于 3D 生物探针的分析物敏感免疫检测，（2）游离和化学吸附金纳米粒子在 3D 生物探针-分析物相关复合物周围的协调组装，随后快速产生明显的光学信号。这种先进的一步式免疫分析已成功应用于需要高精度和/或速度的诊断分析，即通过检测患者血清中的心脏蛋白（肌钙蛋白 I）和抗丙型肝炎病毒抗体来诊断急性心肌梗死和丙型肝炎，表明它适用于广泛疾病的抗原和抗体标志物的准确快速检测。
