High-resolution macro ATR-FTIR chemical imaging capability at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline

Abstract

This presentation aims to provide a summary on technical aspects and applications of our synchrotron macro ATR-FTIR microspectroscopy, unique to the Infrared Microspectroscopy (IRM) beamline at ANSTO–Australian Synchrotron.1 The device was developed by modifying the cantilever arm of a standard macro-ATR unit to accept Ge-ATR elements. Coupling synchrotron-IR beam to the Ge-ATR element (n=4), reduces the beam focus size by a factor of 4 (improving lateral resolution), and the mapping step size by 4 times relative to the stage step motion. As a result, the macro ATR-FTIR measurement at our IRM beamline can be performed at minimum projected aperture (sampling spot size) of 1-2 μm using a 20x objective, and minimum mapping step size of 250 nm, allowing high-resolution chemical imaging analysis with the resolution limit beyond those allowed for standard synchrotron-FTIR transmission and reflectance setups. The technique has facilitated many experiments in a diverse range of research disciplinary. Here, there will be presentations based on macro ATR-FTIR technique in archaeology, electrochemistry (battery), biomedical and forensic sciences. Apart from these, we will provide additional applications in the fields of food and pharmaceutical science,2-4 single-fibre analysis,5-6 and dentistry.7 References: [1] J. Vongsvivut, et al., Analyst 144, 10, 3226-323 (2019). [2] A.P. Pax, et al., Food Chemistry, 291, 214-222 (2019). [3] Y.P. Timilsena, et al., Food Chemistry, 275, 457-466 (2019). [4] D.M. Silva, et al., Journal of Colloid and Interface Science, 587, 499-509 (2021). [5] S. Nunna, et al., Journal of Materials Chemistry A, 5, 7372-7382 (2017). [6] C. Haynl, et al., Scientific Reports, 10, 17624 (2020). [7] P.V. Seredin, et al., International Journal of Molecular Sciences, 22, 6510 (2021). © 2021 The Authors