Department of Chemistry, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
Department of Chemistry, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
Biosens Bioelectron. 2015 Aug 15;70:404-10. doi: 10.1016/j.bios.2015.03.024. Epub 2015 Mar 16.
Rapid and sensitive methodologies for the detection of protein are in urgent requirement for clinic diagnostics. Localized surface plasmon resonance (LSPR) of metal nanostructures has the potential to circumvent this problem due to its sensitive optical properties and strong electromagnetic near-field enhancements. In this work, an enzyme mediated plasmonic biosensor on the basis of a dual-functional nanohybrid was developed for the detection of thrombin. By utilizing LSPR-responsive nanohybrid and anaptamer-enzyme conjugated reporting probe, the sensing platform brings enhanced signal, stability as well as simplicity. Enzymatic reaction catalyzed the reduction of Au(3+) to Au° in situ, further leading to the rapid crystal growth of gold nanoparticles (AuNPs). The LSPR absorbance band and color changed company with the nanoparticle generation, which can be real-time monitoring by UV-visible spectrophotometer and naked eye. Nanohybrid constructed by gold and magnetic nanoparticles acts as a dual functional plasmonic unit, which not only plays the role of signal production, but also endows the sensor with the function of magnetic separation. Simultaneously, the introduction of enzyme effectively regulates the programming crystal growth of AuNPs. In addition, enzyme also serves as signal amplifier owing to its high catalysis efficiency. The response of the plasmonic sensor varies linearly with the logarithmic thrombin concentration up to 10nM with a limit of detection of 200 pM. The as-proposed strategy shows good analytical performance for thrombin determination. This simple, disposable method is promising in developing universal platforms for protein monitoring, drug discovery and point-of-care diagnostics.
快速灵敏的蛋白质检测方法对于临床诊断至关重要。由于金属纳米结构的局域表面等离子体共振（LSPR）具有灵敏的光学特性和强烈的电磁场近场增强，因此有可能解决这个问题。在这项工作中，基于双功能纳米杂化体开发了一种酶介导的等离子体生物传感器，用于检测凝血酶。利用 LSPR 响应纳米杂化体和适配体-酶偶联报告探针，传感平台具有增强的信号、稳定性和简单性。酶促反应原位催化 Au(3+)还原为 Au°，进一步导致金纳米粒子（AuNPs）的快速晶体生长。LSPR 吸收带和颜色与纳米粒子的生成同时变化，可以通过紫外-可见分光光度计和肉眼实时监测。金和磁性纳米粒子构成的纳米杂化体作为双功能等离子体单元，不仅起到信号产生的作用，而且赋予传感器磁性分离的功能。同时，酶的引入有效地调节了 AuNPs 的编程晶体生长。此外，由于其高催化效率，酶还可用作信号放大器。等离子体传感器的响应与凝血酶浓度的对数呈线性变化，检测限低至 200 pM。所提出的策略在凝血酶测定中表现出良好的分析性能。这种简单、一次性的方法有望开发用于蛋白质监测、药物发现和即时诊断的通用平台。
