Integrated on-chip microfluidic system with surface plasmon resonance biosensor for time-effective detection of legionella pneumophila in contaminated water

军团菌是存在于天然水生栖息地的革兰氏阴性细菌，特别是在饮用水、冷却塔和热交换器系统中。当易感宿主吸入雾化水或吸入含有这种细菌的水时，这些细菌会引起人类呼吸道疾病。军团菌攻击肺部，导致危及生命的肺炎。与军团病的相关性最近变得越来越重要，据报道，魁北克省爆发了180例病例和3例死亡。军团菌有50种菌株，其中几乎一半是记录在案的人类病原体。细胞培养是检测水样中军团菌的常用方法。然而，这需要2天；甚至2周时，当一个以上的菌株存在，以获得明确的结果。对于军团菌的物种特异性检测，通常使用从16S rRNA中提取的寡核苷酸进行聚合酶链反应以获得定性信息。最近，在使用芯片实验室设备以及检测病原体的传感技术方面进行了广泛的努力。大多数可用的军团菌传感器集中于检测一种细菌菌株，当样品中含有抑制军团菌生长的微生物时，传感器缺乏灵敏度。在此，我们提出了一种实验室芯片装置，通过集成标签自由表面等离子体共振生物传感器中的数字微流体，用于军团菌16S rRNA的寡核苷酸检测，用于水质控制。充分的信号放大策略和优化的表面化学将实施，以实现高灵敏度，特异性和缩短分析时间。我们的方法包括几种原始方法，主要是开发用于固定DNA探针的适当表面功能化和在可见光谱中工作的光谱角SPR生物传感器

Legionella are gram-negative bacteria found in natural aquatic habitats, especially in potable water, cooling tower and heat exchanger systems. These bacteria cause respiratory disease in humans when a susceptible host inhales aerosolized water or aspirates water containing the bacteria. The legionella attack the lungs and cause a life threatening pneumonia. The relevance to legionnaire's has become ever more relevant as of late, with a reported outbreak in Quebec responsible for 180 cases and 3 deaths. There are 50 bacterial strains belonging to legionella, almost half of which are documented human pathogens. Cell cultures are a common method of testing legionella in water samples. However this requires 2 days; even 2 weeks when more than one strain is present, to obtain definitive results. For species-specific detections of Legionella, oligonucleotides derived from the 16S rRNA are often used in polymerase chain reaction to obtain qualitative information. More recently, there have been extensive efforts invested in the use lab-on-a-chip devices along with the sensing technology for the detection of pathogens. Most available sensors for legionella focus on detecting one strain of the bacteria and lacks sensitivity when samples contain microroganisms that inhibit legionella growth. Herein we propose a lab-on-a chip device for the oligonucleotides derived from the 16S rRNA detection of legionella for water quality control through the integration of a digital microfluidics within label free surface plasmon resonance biosensors. Adequate signal amplification strategies and optimized surface chemistry will be implemented to achieve high sensitivity, specificity and reduced assay time. Our methodology entails several original approaches, mainly the development of a proper surface functionalization for the immobilization of DNA probe and a spectro-angular SPR biosenor working in the visible spectrum compatible with our developed digital microfluidics device. Such a platform would offer the possibility of sample handling, mixing, and real time on-chip detection of 16S rRNA from multiple strains of the legionella with high sensitivity and will provide quantitative information using only a few hundred nanoliters of contaminated water.