Seeing it in a different light: chemical imaging of polymeric and biomedical materials

FTIR spectroscopic imaging has emerged as a powerful tool for characterisation of polymeric and biomedical samples. Shining infrared light on substances opens up the language of molecules. FTIR imaging relies on the ability of the infrared array detector to measure spectra from thousands of different locations in a sample simultaneously. FTIR imaging enhances research at the interdisciplinary interfaces, stretching the boundaries between traditional science and engineering. This talk will outline the research we are developing in this area with focus on ATR (Attenuated Total Reflection)-FTIR spectroscopic imaging. The advances range from polymeric materials, pharmaceuticals to biomedical samples and forensics. Chemical visualisation with enhanced spatial resolution in _micro_ ATR imaging mode broadens the range of samples (polymer blends, pharmaceutical tablets, cross-sections of blood vessels or hair, surface of skin, single cells, etc.) amenable to study with FTIR imaging which were previously ruled out by the inadequate spatial resolution. Recent developments in _macro_ ATR imaging with the use of inverted prism crystals show good potential with applications to protein crystallization, imaging of flows in microfludics and imaging of live cancer cells. The opportunity to obtain chemical images of the same sample from different depths through the use of macro ATR-FTIR imaging with variable angles of incidence has also been demonstrated. The ability to make spatially resolved chemical snapshots as a function of time is the basis of dynamic chemical imaging offered by macro ATR imaging approach.