Size dependent fluorescence and Raman characterization of nanoparticles by means of a novel analytical ultracentrifuge

颗粒特性取决于分散性(颗粒大小、形状、表面和内部结构)和组成。为了在技术应用中充分开发这些性质功能，需要综合的多维表征方法。近年来，集成多波长吸收光学的分析超速离心法领域的发展已经证明了尺寸、形状、密度和光谱吸收性质表征的无与伦比的分辨率、准确性和重复性。这项建议的目的是在分析性超速离心机中发展原位荧光和拉曼光谱。通过测量在可调离心场中沉淀过程中的荧光光谱，可以同时表征纳米颗粒的分散特性，包括尺寸、形状、密度以及第一次的发射特性。沉淀过程中颗粒的分离可以获得更广泛的分布，并允许确定依赖于分散性的发射特性。这种新方法适用于量子点、等离子体贵金属胶体、新型2D材料和蛋白质及其聚集体。拉曼分析可以获得依赖于大小的颗粒组成和结构(例如，碳同素异形体，如碳纳米点、石墨烯或碳纳米管)。在本项目中，新的光学装置应集成到预备性超离心机中，并使用参考材料进行验证。下一步包括开发新的测量方法和数据采集软件。对各种尖端粒子系统的测量将展示新的能力，并将使人们对所研究的粒子系统有更深的了解。

Particle properties depend on dispersity (particle size, shape, surface and inner structure) and composition. In order to fully exploit these property functions in technical applications, comprehensive multi-dimensional characterization methods are required. Developments in recent years in the field of analytical ultracentrifugation with integrated multi-wavelength absorption optics have already demonstrated the unmatched resolution, accuracy and reproducibility of size, shape, density and spectral absorption property characterization. Objective of this proposal is the development of in situ fluorescence and Raman spectroscopy within an analytical ultracentrifuge. The measurement of fluorescence spectra during sedimentation in an adjustable centrifugal field enables the simultaneous characterization of disperse properties including size, shape, density and, for the first time, also the emissive properties of nanoparticles. The separation of the particles during sedimentation gives access to even broad distributions and allows the determination of dispersity-dependent emission properties. The new method is applicable for quantum dots, plasmonic noble metal colloids, new 2D materials and proteins and their aggregates. Raman analysis gives access to size-dependent particle composition and structure (e.g. for carbon allotropes such as carbon nanodots, graphene or CNTs). Within this project, the new optical setup shall be integrated into a preparative ultracentrifuge and validated with reference materials. The next steps comprise the development of novel measurement methods and data acquisition software. Measurements for various cutting-edge particle systems shall demonstrate the new capabilities and will allow deeper understanding of the studied particle systems.