Multiscale Analysis of Mineralized Collagen Combining X-ray Scattering and Fluorescence with Raman Spectroscopy under Controlled Mechanical, Thermal, and Humidity Environments

Biological materials, such as mineralized collagen, are structured over many length scales. This represents a challenge for quantitative characterization, in particular when complex specimen environments are required. This paper describes an approach based on synchrotron X-ray scattering and Raman spectroscopy to analyze the structure of biological materials from the molecular to the macroscopic range in controlled environments including humidity, temperature, and mechanical load. This is achieved by a new setup, installed at the microfocus beamline μSpot at the BESSY II synchrotron in Berlin, where a perforated mirror is placed into the X-ray beam to focus laser light into the specimen to excite a Raman signal. We show that this allows simultaneous micrometer-scale mapping of chemical groups in the organic matrix together with the size and orientation of mineral nanoparticles in mineralized collagen. The approach is especially suitable to studying time-dependent modifications of materials, such as molecular changes during tensile deformation, dehydration, or thermal denaturation.