研究人员迈出研发生物传感器检测细菌的第一步

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检索：陈志锦翻译：王宁宁审核：陈志锦
马德里政治大学（UPM）的研究人员已经迈出了研发传感器的第一步，通过将重力传感器和合成抗体结合，可实时发现细菌性脑膜炎，这是一种灵敏、快速、经济的细菌检测方法。
为了开发细菌性疾病的早期诊断方法，来自马德里政治大学(UPM)高级ICT材料和设备中心(CEMDATIC)的微系统和电子材料研究小组（GMME）发表了一篇论文介绍初步研发细菌性脑膜炎相关的细菌检测生物传感器。
通过这种方式，研究人员使用重力传感器与作为受体的适体结合。这种方法比现在使用的方法更快速、更经济，而且可以在卫生保健中心用于早期诊断细菌性疾病。
细菌性脑膜炎是全球十大感染性疾病致死原因之一。约有10%的患者在症状发作后的24-48小时内死亡，而且其中10%-20%的细菌性脑膜炎幸存者伴有长期的神经系统损伤症状。此外，细菌性脑膜炎很容易通过咳嗽、打喷嚏或密切接触传播。
这些问题对于疾病的快速和准确诊断是至关重要的，以便为患者提供准确的治疗及预防可能发生的流行病。细菌脑膜炎最常见致病菌是脑膜炎球菌和肺炎链球菌，但是其早期临床诊断通常是非特异性的，这使得细菌的快速识别变得困难。早期诊断对疫情的适当治疗至关重要。
现今，确诊的方法持续时间太长或费用昂贵，而且需要有高素质医务人员的参与。鉴于这种情况， CEMDATIC-UPM的研究人员旨在通过使用传感器来提高诊断水平以便能够更快、更廉价、更灵敏地诊断。因此，他们使用无标记的生物传感器来直接检测整个细菌。
无标记重力式生物传感器是由两个基本电声谐振器受体组成。第一个受体是能够选择和有效地固定待研究的物种材料，使得其重量与待分析的流体中的这些物质的浓度成比例地增加。 第二个受体是传感器，负责在检测物种时测量受体的重量变化。
UPM研发的生物传感器使用适配体作为受体，因为它们是一种理想的替代物，在亲和生物传感器中被用于替代识别生物抗体。这些受体是化学性状非常稳定的人工合成物，且具有可选择性，它们可以为每个物种专门设计。除此之外，他们还使用了重力传感器作为高频剪切型薄膜谐振器的传感器。
这种生物传感器是一种有趣的选择方案，因为它具有灵敏度高、检测极限低和成本低的特点。研究人员通过测量重力传感器共振频率的变化来测试这种新方法的有效性。生物传感器能够检测出在特别低浓度下引起脑膜炎的特异性细菌蛋白质。
研究人员认为，这项工作的开展为用于检测细菌性疾病研发出快捷、经济实惠且非常敏感的生物传感器的发展铺平了道路。这将提高这类疾病的早期诊断水平，同时也是避免严重并发症的一个关键因素。



原
文

Researchers take first steps towards development of biosensor for detection of bacteria

Researchers from UPM have taken the first steps towards the development of a sensor for the detection of bacterial meningitis in real time by combining gravimetric sensors with synthetic antibodies giving, as a result, a sensitive, rapid and affordable method.


In order to develop early diagnosis methods of bacteria diseases, the team of researchers from Microsystems and Electronic Materials Group (GMME) at Center for Advanced ICT Materials and Devices (CEMDATIC) of Universidad Politécnica de Madrid (UPM) has published a work to explain the first steps towards the development of a biosensor for the detection of bacteria associated with bacterial meningitis


In this way, researchers used gravimetric biosensors combined with aptamers that act as receptors. This method is more rapid and affordable than the methods used today, and they could be used in health care centers for early diagnosis of bacterial diseases.


The bacterial meningitis is among the top 10 causes of death due to infectious diseases worldwide. About 10% of patients die within the following 24-48 hours after onset of symptoms, and 10% to 20% of the survivors of this disease present long term neurological damages. Besides, bacterial meningitis is easily spread through coughing, sneezing or close contact.


These issues make essential a rapid and accurate diagnosis of the disease in order to provide patients with adequate treatment and prevent a possible epidemic. The bacteria most commonly associated with bacterial meningitis are the meningococcal and pneumococcus, but its early clinical diagnosis is often nonspecific, and this makes difficult the rapid identification of the bacteria, being critical for an appropriate treatment of the outbreak.


Today, the diagnosis confirmation is often based on methods that last too long or are expensive and require the intervention of highly qualified personnel. Being aware of the situation, CEMDATIC-UPM researchers aimed to improve the diagnosis of these types of diseases by using sensors that allow them a faster, cheaper and more sensitive diagnosis. Therefore, they used label-free biosensors for direct detection of whole bacteria


The label-free gravimetric biosensors consist of electroacoustic resonators based on two basic elements. The first receptor is a material able to fix the species to be studied selectively and efficiently, in such way that its weight increases proportionally to the concentration of such species in the fluid to be analyzed. The second element, the transducer, is in charge of measuring the variation of the weight of the receptor when detecting the species.


The biosensor developed by UPM uses aptamer as receptors since they are a very attractive alternative when it comes to replacing the antibodies for the biorecognition of species in affinity biosensors. These receptors are very chemically stable, synthetics (against the antibodies developed in animals) and selective (they can be designed specifically for each species). Besides, they used gravimetric sensors as transducers based on high-frequency shear mode thin film resonators.


This biosensor is an interesting alternative because of its high sensitivity, low detection limit, and low cost. Researchers have confirmed the effectiveness of this new method by testing, through the measurement of the variations of the resonance frequency of the gravimetric sensor, that the biosensor is able to detect specific proteins of bacteria causing meningitis in exceptionally low concentrations.


According to the researchers, this work paves the way towards the development of rapid, affordable and very sensitive biosensors for the detection of bacterial diseases. This will improve the early diagnosis of this type of diseases which is a key aspect to avoid serious complications.





图文：朱迪