Rapid diagnostic biosensors for the detection of respiratory viruses (VIRASENS)

呼吸道合胞病毒（RSV）和其他病毒，如流感，是广泛和严重的感染，在幼儿和老年人中尤为重要。例如，呼吸道合胞病毒在早期阶段的表现与细菌感染非常相似，但所需的治疗方法根本不同，例如抗病毒或抗菌。无论哪种方式，错误的决定都会导致时间的浪费和并发症，而这些都可以通过早期准确的诊断来避免。因此，这些疾病是需要即时诊断（POC）而不是需要将样本送到中心实验室的系统的主要例子。有一系列POC的方法，包括简单的侧流装置，如妊娠试验中使用的那些。Orla蛋白质技术有限公司是一家利用BBSRC资助的研究成果设计敏感表面的公司，该表面允许电子设备检测生物分子。这些表面用于各种系统，但在这项研究中，他们采用了与日本领先的无线通信公司日本无线电公司合作生产的表面声波传感器。该设备，表面声波（或SAW）传感器是众所周知的音叉的电子版本，具有自己定义的音符或共振频率。如果小分子与设备表面结合，那么这种特征音符就会发生变化，并且可以通过电子方式检测到。然后，信号与病人信息、时间、温度甚至GPS读数一起无线发送到一个中央设备。因此，结果被自动记录下来，避免了人为错误。医生能立即得到答案，并能迅速而恰当地开出处方。所有这一切都取决于检测的质量，它依赖于一个5纳米厚的层，可以识别病毒的特征蛋白质。5纳米比一张标准A4纸薄3万倍，因此这一层是分子尺度工程的一个例子。Orla使用的分子可以自组装成一个定向层，这是由于他们的设计，因此在设备上组装的方式比油漆/想象油漆一个房间更容易，只需在墙上扔一桶丝绸乳液，最终形成一个完美的层，避免了木制品，天花板和地板！其中的诀窍在于混合物的分子设计，其中大部分是蛋白质工程。蛋白质是我们希望识别的目标，通常我们使用其他蛋白质来识别它们。最好的例子是在老鼠体内产生的抗体，这些抗体被选择用来识别RSV或其他病毒蛋白。这个小组的研究项目将创造工程蛋白，这些蛋白将与抗体一起组装，在SAW设备上形成一个高度选择性的单层。这包括修改自组装蛋白质以制造非常稳定和精确定向的抗体结合阵列，通过生物物理方法检查这些蛋白质的结构，在模型表面上组装蛋白质，如SAW设备上的蛋白质，并测量所得层的行为。该公司将在潜在客户手中对这些设备进行实际情况下的测量。因此，Lakey团队将专注于该层的分子工程，并将通过其在蛋白质工程方面的设施和专业知识为该项目增加价值。作为初步步骤，我们还将利用我们的生化知识从VIRATOM提供的无菌材料中纯化病毒抗原。这些对于质量控制目的是必不可少的，并且将为校准和提高设备的灵敏度和选择性提供重要资源。该项目的最终结果将是一个高度选择性和敏感的自组装层，可以直接转移到商用SAW器件的大规模生产中。

Respiratory syncytial virus (RSV) and others, such as influenza, are widespread and serious infections especially important in the very young and the very old. RSV for example presents in its early stages much like bacterial infections but the treatment required is fundamentally different e.g. anti /viral or anti bacterial. The wrong decision, either way, leads to lost time and complications which can be avoided by early accurate diagnosis. These diseases are thus prime examples of the need for point of care (POC) diagnosis rather than systems which require samples to be sent to a central laboratory. There are a range of approaches to POC including simple lateral flow devices like those used in pregnancy tests. Orla Protein Technologies Ltd is a company using the results from BBSRC funded research to design sensitive surfaces which allow electronic devices to detect biological molecules. These surfaces are used in a variety of systems but for this study they are employing a surface acoustic wave sensor manufactured in collaboration with a leading Japanese wireless communication firm, the Japan Radio Company. The device, a surface acoustic wave (or SAW) sensor is an electronic version of the well known tuning fork with its own defined note or resonant frequency. If small molecules bind to the surface of the device then this characteristic note changes and can be detected electronically. The signal is then sent wirelessly to a central device along with patient information, time, temperature and even a GPS reading. Thus the results are automatically logged and human error is avoided. The physician gets an immediate answer and can prescribe quickly and appropriately.All this depends upon the quality of the detection which relies upon a 5 nm thick layer which recognises characteristic proteins from the virus. Five nanometres is 30,000 times thinner than a sheet of standard A4 paper and the layer is thus an example of molecular scale engineering. Orla uses molecules which self-assemble into an oriented layer due to their design, thus the assembly upon the device are accomplished in a manner easier than painting / imagine painting a room by simply throwing a bucket of silk emulsion on the walls and ending up with a perfect layer that avoids the woodwork, ceiling and floor! The trick to this is in the molecular design of the mixture and much of this is protein engineering. Proteins are the target that we wish to recognise and usually we use other proteins to recognise them. The best examples of these are antibodies, produced in mice, which have been selected to recognise RSV or other viral proteins. The research project in this group will create engineered proteins that will co assemble with the antibodies to create a highly selective monolayer on the SAW device. This involves modifying the self assembling proteins to make very stable and precisely oriented antibody binding arrays, checking the structure of these proteins by biophysical methods, assembly of the proteins on model surfaces like the ones present on the SAW device and measurement of the resulting behaviour of the layers. The company will carry out measurements upon the devices under real life situations in the hands of prospective customers. The Lakey group will thus concentrate on the molecular engineering of the layer and will add value to the project by its access to facilities and expertise in protein engineering. As a preliminary step we will also use our biochemical knowledge to purify viral antigens from sterile materials supplied by VIRATOM. These are essential for quality control purposes and will provide an important resource to calibrate and improve the sensitivity and selectivity of the device. The final result of the project will be a highly selective and sensitive self assembling layer which can be transferred directly into the mass manufacture of the commercial SAW device.