School of Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, UK.
Anal Chem. 2012 Jan 3;84(1):91-7. doi: 10.1021/ac201544h. Epub 2011 Dec 12.
Biomolecular detection has for a long time depended on a relatively small number of established methodologies. Many of these depend on the detection of a ligand-antibody complex using some kind of optical technique, e.g., chemiluminescence. Before this measurement can be made, the ligand-antibody complex generally has to be separated from bulk contaminants. This process involves the implementation of a heterogeneous assay format involving immobilization of the antibody onto a solid support to enable washing of the unbound ligand. This approach has a number of inherent issues including being slow and complex and requiring the use of expensive reagents. In this paper, we demonstrate how we have harnessed a biologically inspired nanoparticle to provide the basis for a homogeneous assay which requires no immobilization. The method relies on using fluid shear flow to align a fiber-like nanoparticle formed from a filamentous virus, M13, combined with a ligand-specific antibody. This renders the particle visible to linear dichroic spectroscopy, which provides an easily interpretable signal. The addition of the target ligand (in this case Escherichia coli O157) leads to the formation of a nanoparticle-ligand particle that is unable to align, leading to the perturbation of the linear dichroism signal.
生物分子检测长期以来一直依赖于少数几种既定的方法。其中许多方法依赖于使用某种光学技术检测配体-抗体复合物，例如化学发光。在进行此测量之前，通常必须将配体-抗体复合物从大量杂质中分离出来。该过程涉及实施涉及将抗体固定到固体支持物上的异质测定格式，以实现未结合的配体的洗涤。这种方法有许多固有的问题，包括速度慢、复杂，并且需要使用昂贵的试剂。在本文中，我们展示了如何利用受生物启发的纳米粒子为不需要固定化的均相测定提供基础。该方法依赖于使用流体剪切流来对准由丝状病毒 M13 形成的纤维状纳米粒子，该纳米粒子与配体特异性抗体结合。这使得粒子对线性二色性光谱可见，该光谱提供了易于解释的信号。添加靶配体（在这种情况下是大肠杆菌 O157）会导致形成无法对齐的纳米粒子-配体颗粒，从而导致线性二色性信号的干扰。
