Time-of-Flight - Secondary Ion Mass Spectrometry (ToF-SIMS): exploring the sources and distributions of microbial biomarkers at the µm-range

飞行时间二次离子质谱仪(ToF-SIMS)是一种无需提取样品即可检测表面无机和有机分子的技术。此外，ToF-SIMS能够在微观水平上显示检测到的任何离子的强度，因此远远超过了生物标记物研究中常规使用的基于提取的技术所能达到的分辨率。本项目的目标是为进一步提高TOF-SIMS成像质谱学在地球生物学中的应用提供基础研究和实验工作。在第一个项目期间，已经获得了关于标准生物标志物化合物和人工实验装置的基础数据。在这份更新提案中，重点是使用成像质谱仪对从Aespöhard Rock实验室和基里蒂马蒂盐湖取样的环境调节膜、生物膜和微生物垫进行分析。为了加强获得的光谱数据的重要性，计划将TOF-SIMS与统计分析和显微技术，特别是常规显微镜和扫描电子显微镜(SEM)联系起来。提高对有机分子在微观水平上的空间定位的认识将有助于更好地了解生物矿化的机制，以及微生物系统中复杂的生态相互作用，并将允许更明确地将脂质生物标记物与其生物来源相关联。

Time of Flight - Secondary Ion Mass Spectrometry (ToF-SIMS) is a technique that detects inorganic and organic molecules on surfaces, without the need to extract the sample in question. Moreover, ToF-SIMS is able to display at the microscopic level the intensities of any ion detected, thus exceeding by far the resolution achievable with the extract-based techniques routinely used in biomarker studies. The objective of the current project is to provide basic research and experimental work to further advance the utility of ToF-SIMS imaging mass spectrometry for geobiological applications. During the first project term, fundamental data have been obtained on standard biomarker compounds and artificial experimental setups. In this renewal proposal, emphasis will be placed on using imaging mass spectrometry on environmental conditioning films, biofilms, and microbial mats sampled from the Äspö Hard Rock Laboratory and saline lakes on Kiritimati. In order to enhance the significance of the spectral data obtained, it is planned to link ToF-SIMS with statistical analysis and microscopic techniques, particularly conventional microscopy and scanning electron microscopy (SEM). Enhanced knowledge about the spatial localization of organic molecules at the microscopic level will enable a better understanding of the mechanisms of biomineralization, the complex ecological interactions in microbial systems, and will allow for a more clear-cut association of lipid biomarkers with their biological source.