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Visible to Mid-IR Spectromicroscopy with Top-Down Illumination and Nanoscale (≈ 10 nm) Resolution



Devon Jakob, Andrea Centrone


Photothermal induced resonance (PTIR), an atomic force microscopy (AFM) analogue of IR spectroscopy capable of nanoscale lateral resolution, finds broad applications in biology and materials science. Here, the spectral range of a top-illumination PTIR setup operating in contact-mode is expanded for the first time to the visible and near-IR spectral ranges. The result is a tool that yields spectra and maps of electronic and vibrational features with spatial resolution down to ≈ 10 nm. In addition to the record-breaking (for contact-mode PTIR) resolution, the setup enables light-polarization dependent PTIR experiments in the visible and near-IR ranges for the first time. While previous PTIR implementations in the visible used total internal reflection illumination requiring challenging sample preparations on a optically transparent prism, the top-illumination used here greatly simplifies sample preparation and will foster a broad application of this method.
Analytical Chemistry


Jakob, D. and Centrone, A. (2022), Visible to Mid-IR Spectromicroscopy with Top-Down Illumination and Nanoscale (≈ 10 nm) Resolution, Analytical Chemistry, [online],, (Accessed July 21, 2024)


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Created November 2, 2022, Updated November 29, 2022