Chemical dynamics in biological samples are seldom stand-alone processes but represent the outcome of complicated cascades of interlinked reaction chains. In order to understand these processes and how they correlate, it is important to monitor several parameters simultaneously at high spatial and temporal resolution. Hyperspectral imaging is a promising tool for this, as it provides broad-range spectral information in each pixel, enabling the use of multiple luminescent indicator dyes, while simultaneously providing information on sample structures and optical properties. In this study, we first characterized pH- and O₂-sensitive indicator dyes incorporated in different polymer matrices as optical sensor nanoparticles to provide a library for (hyperspectral) chemical imaging. We then demonstrate the successful combination of a pH-sensitive indicator dye (HPTS(DHA)₃), an O₂-sensitive indicator dye (PtTPTBPF), and two reference dyes (perylene and TFPP), incorporated in polymer nanoparticles for multiparameter chemical imaging of complex natural samples such as green algal biofilms (Chlorella sorokiniana) and seagrass leaves (Zostera marina) with high background fluorescence. We discuss the system-specific challenges and limitations of our approach and further optimization possibilities. Our study illustrates how multiparameter chemical imaging with hyperspectral read-out can now be applied on natural samples, enabling the alignment of several chemical parameters to sample structures.

中文翻译：

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通过发光传感器纳米粒子的高光谱成像对生物界面处的氧气和 pH 值进行多参数传感

生物样品中的化学动力学很少是独立的过程，而是代表相互关联的反应链的复杂级联的结果。为了了解这些过程及其相互关系，以高空间和时间分辨率同时监测多个参数非常重要。高光谱成像是一种很有前景的工具，因为它可以在每个像素中提供广泛的光谱信息，从而可以使用多种发光指示剂染料，同时提供有关样品结构和光学特性的信息。在这项研究中，我们首先将不同聚合物基质中的 pH 和 O ₂敏感指示剂染料作为光学传感器纳米颗粒进行表征，为（高光谱）化学成像提供库。然后，我们展示了 pH 敏感指示剂染料 (HPTS(DHA) ₃ )、O ₂敏感指示剂染料 (PtTPTBPF) 和两种参考染料（苝和 TFPP）的成功组合，将其合并到聚合物纳米颗粒中用于多参数化学成像复杂的天然样品，例如具有高背景荧光的绿藻生物膜 ( Chlorella sorokiniana ) 和海草叶 ( Zostera marina )。我们讨论了我们的方法的特定于系统的挑战和局限性以及进一步优化的可能性。我们的研究说明了如何将具有高光谱读出的多参数化学成像应用于自然样品，从而使多个化学参数与样品结构对齐。