Raman imaging of materials in the natural environment

绝大多数关于生物对环境变化的化学反应的研究都是在受控的实验室条件下对模式物种和系统进行的。对生活在自然环境中的物种的研究相对较少，目前尚不清楚从同质条件中收集的见解如何反映复杂环境中运作的过程。填补这一空白需要可在实地部署的实验室级设备，以便在其复杂和动态的环境背景下可靠地捕捉生物多样性和生态过程的全部广度。拉曼成像光谱提供了异常高分辨率，空间明确的化学信息横跨样品表面。例如，该方法已用于植物科学，以揭示新的机制，例如植物生产稀有矿物。然而，到目前为止，共聚焦成像拉曼能力仅限于实验室使用。雷尼绍英国公司最近开发了第一台便携式共聚焦成像拉曼光谱系统，该系统首次可用于以最高的空间和光谱精度绘制现场样品的化学图谱。这项新技术将使研究人员能够以以前不可能的规模就地测量化学结构和跟踪过程；这种新能力有望揭示迄今为止隐藏的生态成分和过程。要实现这一潜力，首先需要将现场仪器（Virsa）与类似的实验室系统（inVia）进行校准。这些雷尼绍成像拉曼系统提供了独特的能力，使它们特别适合分析环境样品：LiveTrack聚焦允许在粗糙表面上进行化学测绘，而无需改变或样品制备；超高速探测器可以在最短的时间内测量大样本区域；该检测器还具有高灵敏度，使其能够在异质样品中甚至在光学噪声环境中捕获低浓度分子；它的目标化合物的测量能力进一步减少了分析时间，这允许比标准化学分析方法更大的复制。与所有拉曼系统一样，它们能够捕获活组织中的有机和无机分子，因为该方法对水不敏感（与红外光谱不同）。inVia和Virsa系统共同提供了一种全新的功能，可以在从环境样品中获得的化学和结构信息的类型、精度和数量上实现跨步变化。我们将利用这一能力来回答有关植物-土壤反馈，土壤微生物过程和有机体对胁迫反应的紧迫问题。在每个项目中，我们将根据inVia的测量结果校准Virsa，为拉曼共聚焦成像在实地研究中的广泛采用奠定基础。我们将通过多种途径（培训、出版、合作）来扩大人们对这种新型设备在NERC范围内为环境研究提供的能力的认识。

The vast majority of research on chemical responses by organisms to environmental change are conducted on model species and systems within controlled laboratory conditions. There are comparatively fewer studies on species living in the natural environment and it remains unclear how well insights gleaned from homogeneous conditions reflect processes operating in complex environments. Filling this gap requires laboratory-grade equipment that can be deployed in the field to reliably capture the full breadth of biodiversity and ecological processes within their complex and dynamic environmental context. Raman imaging spectroscopy provides exceptionally high-resolution, spatially explicit chemical information across a sample surface. The method has been used in plant sciences, for example, to uncover novel mechanisms, e.g. plant production of rare minerals. However, until now, confocal imaging Raman capability has been limited to laboratory use. Renishaw UK recently developed the first portable, confocal imaging Raman spectroscopy system, which - for the first time - can be used to map the chemistry of samples in the field with the highest possible spatial and spectral precision. This new technology will enable researchers to measure chemical structure and track processes in situ at a scale previously impossible; this new capability promises to shed light on heretofore hidden ecological components and processes. Fulfilling this potential firstly requires calibration of the field-based instrument (the Virsa) against a comparable laboratory-based system (the inVia).These Renishaw imaging Raman systems offer unique capability that makes them particularly well-suited for analysing environmental samples: LiveTrack focusing allows for chemical mapping over a rough surface without alteration or sample preparation; the ultra-fast detector enables large sample areas to be measured in minimal time; the detector is also highly sensitive which allows it to capture low concentration molecules within a heterogenous sample and even within an optically noisy environment; and its ability to target compounds for measurement further reduces analysis time, which allows for far greater replication than is feasible with standard chemical analysis methods. As with all Raman systems, they are able to capture both organic and inorganic molecules in living tissues because the method is insensitive to water (unlike infrared spectroscopy). Together, the inVia and Virsa systems offer novel capability that will create a step change in the type, precision and amount of chemical and structural information that can be obtained from environmental samples. We will take advantage of this capability to answer pressing questions about plant-soil feedbacks, soil microbial processes and organismal responses to stress. Within each project, we will calibrate the Virsa against measurements taken by the inVia in order to set the foundation for widespread adoption of Raman confocal imaging in field research. We will use a number of routes (training, publication, collaborations) to broaden awareness of the capability this novel equipment offers environmental research across the NERC remit.