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 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 therapeutic solutions to improve oral health.

了解生物膜的动态环境微生态将使我们能够检测、管理和利用这些社区。对生物膜的成分和结构进行了深入研究；然而，人们对目前的环境微生态知之甚少。这主要是因为缺乏具有所需测量灵敏度和分辨率的工具来检测这些变化。我们描述了比率荧光 pH 敏感纳米传感器作为一种工具的应用，以实时观察生物膜中的生理 pH 变化。纳米传感器包含两个 pH 敏感荧光团，它们与一个参考 pH 不敏感荧光团共价封装在惰性聚丙烯酰胺纳米颗粒基质中。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：铜绿假单胞菌和 (ii) 口腔病原体变形链球菌。通过纳米传感器实时检测糖代谢为确定改善口腔健康的治疗解决方案提供了潜在的应用。