Confocal Raman microscope with scanning probe unit for correlative imaging

对于我们的生物组织、细胞、蛋白质复合体以及亚微观氧化物颗粒的研究项目，我们申请了具有扫描探针和近场单元的高分辨率共聚焦拉曼激光显微镜来进行相关成像。拉曼光谱用激光激发样品，并用光谱仪分析背散射的光。光谱包含有关样品分子结构的特定信息。使用共聚焦拉曼显微镜，光谱可以以大约300纳米的空间分辨率成像，这使得可以可视化和识别主要细胞器--而不需要组织学染色技术(无标记成像)。在相关拉曼扫描探针显微镜中，扫描探头尖端被用来额外收集关于形貌、分子间力、电场和磁场以及磁场的信息，当这些信息叠加在来自拉曼光谱的分子信号上时，可以得到关于样品物理化学性质的全面图像。使用扫描近场探头(SNOM)，可以从分辨率低于100纳米的样品的近表面区域提取光谱。显微镜旨在加强目前由奥尔登堡大学资助的各种项目，并允许对新的研究项目进行初步分析。特别是，我们正计划在DFG资助的合作研究中心SFB1372(自2019年以来资助)内的一些项目中使用该显微镜，目的是识别和表征动物组织中假定的磁性感觉细胞。磁性活跃的感觉结构不能用传统的显微镜技术进行识别，这就是为什么我们在这里设想一种高分辨率的相关拉曼扫描探针-显微扫描方法。我们将进一步使用显微镜来研究微生物学主题，如单细胞藻类的细胞器结构，细菌等克隆种群中代谢异质性的量化，以及利用Fe-S中心的共振拉曼跃迁来表征硫酸盐还原细菌细胞膜中的氧化还原蛋白。该显微镜还将用于无机化学中光催化和电催化材料材料(过渡金属氧化物颗粒)的表征。

For our research projects on biological tissues, cells, protein complexes as well as on sub-microscopic oxide particles, we apply for a high-resolution confocal Raman laser microscope with scanning probe and near field units for correlative imaging. Raman-spectroscopy excites a sample with a laser and analyzes the backsacttered light with a spectrometer. The spectrum contains specific information about the molecular structure of the sample. With a confocal Raman microscope, spectra can be imaged with a spatial resolution of ca. 300 nm, which allows for visualization and identification of major cell organelles – without histological staining techniques (label free imaging). In correlated Raman-Scanning-Probe-Mikroscopy, a scanning probe tip is used to additional collect information about topography, intermolecular forces, electric and magnetic fieldsund magnetische fields, which when superimposed on the molecular signal from Raman-spectra produces comprehensive picture about the physico-chemical properties of a sample. With a scanning near field probe (SNOM), spectra can be extracted from the near-surface region of a sample with resolution below 100 nm.The microscope is intended to strengthen various projects that are currently funded at the University of Oldenburg and to allow preliminary analysis for new research projects. In particular, we are planning on using the microscope for a number of projects within the DFG funded collaborative research center SFB1372 (funded since 2019) with the aim to identify and characterize putative magnetic sensory cells in animal tissues. The magnetically active sensory structures defy identification by conventional microscopy techniques, which is why we here envisage a high resolution correlative Raman-scanning probe-microscpy approach. We will further use the microscope to for microbiological topics, such as organelle structure of single-celled algae, quantitation of metabolic heterogeneity in isoclonal populations of bacteria, as well as for the characterization of redoxaktive proteins in the cell membrane of sulfate-reducing bacteria taking advantage of resonant Raman transitions in Fe-S centers. The microscope will also be used in inorganic chemistry for the characterisation of photocatalytic and electrocatalytic materials materials (transition metal-oxide particles).