Understanding the dynamic environmental microniches of biofilms will permit us to detect, manage and exploit these communities. The components and architecture of biofilms have been interrogated in depth, however, little is known about the environmental microniches present. This is primarily because of the absence of tools with the required measurement sensitivity and resolution to detect these changes. We describe the application of ratiometric fluorescent pH-sensitive nanosensors, as a novel tool, to observe physiological pH changes in biofilms in real-time. Nanosensors comprised two pH-sensitive fluorophores covalently encapsulated with a reference pH-insensitive fluorophore in an inert polyacrylamide nanoparticle matrix. The nanosensors were used to analyse the real-time three-dimensional pH variation for two model biofilm formers: (i) opportunistic pathogen Pseudomonas aeruginosa, and (ii) oral pathogen Streptococcus mutans. The detection of sugar metabolism in real time by nanosensors provides a potential application to identify novel therapeutic solutions to improve oral health.

中文翻译：

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荧光纳米传感器揭示生物膜形成过程中的动态pH梯度。

了解生物膜的动态环境微生态位将使我们能够发现，管理和利用这些群落。生物膜的成分和结构已被深入研究，但是对目前的环境微环境知之甚少。这主要是因为缺少具有所需的测量灵敏度和分辨率以检测这些变化的工具。我们描述了比例荧光pH敏感型纳米传感器的应用，作为一种新型工具，可以实时观察生物膜中的生理pH值变化。纳米传感器包括在惰性聚丙烯酰胺纳米颗粒基质中与参考pH不敏感荧光团共价封装的两个pH敏感荧光团。纳米传感器用于分析两种模型生物膜形成剂的实时三维pH变化：（i）机会病原体铜绿假单胞菌，和（ii）口腔病原体变形链球菌。纳米传感器实时检测糖代谢，为识别新型治疗方法以改善口腔健康提供了潜在的应用。