Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Infrared (IR) spectroscopy is a powerful method for mapping chemical heterogeneity on the microscale. Synchrotron IR radiation uniquely provides a high brightness and broad bandwidth to further extend the capabilities of IR spectroscopic imaging. However, the diffraction-limited spatial resolution of IR spectroscopy is insufficient for studies requiring submicrometer spatial differentiation. Optical photothermal IR (O-PTIR) microscopy is a powerful, emerging method that overcomes the IR diffraction limit in IR hyperspectral imaging by employing a modulated IR beam and a visible probe laser beam to detect local temperature-induced modulation at the visible diffraction limit. In this work, we extend the spectral range of photothermal infrared measurements by incorporating a synchrotron IR source, demonstrating a combined synchrotron-based O-PTIR modality that enables high spatial resolution far-field chemical imaging spanning the entire mid-IR range. Both optical- and fluorescence-detected photothermal modalities were performed using a step-scan interferometer, demonstrating improved spectral range (541–4000 cm –1 ) when compared to optical photothermal microscopy with commercial laser sources (800–1800 cm –1 for this particular source) and improved spatial resolution, when compared to synchrotron microspectroscopy measurements. Following these initial validation studies, synchrotron Fourier-transform fluorescence-detected photothermal IR spectroscopy in combination with synchrotron microspectroscopy measurements was used to differentiate cells in mouse brain tissue sections, which requires submicron spatial resolutions beyond those accessible by IR spectroscopy alone.
Source: Analytical Chemistry
Authors: Aleksandr Razumtcev, Gwendylan A. Turner, Sergey Zayats, Ferenc Borondics, Aris Polyzos, Garth J. Simpson, Hans A. Bechtel
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1079818582, MRI: Track 1 Development of a Dual-Comb Fluorescence-Detected Photothermal Mid-Infrared (DC-FPTIR) Microscope, G1286236842, G1863003419, Nonlinear Optical Analysis of Molecular Composition and Dynamics within Heterogeneous Assemblies, G30714459, G3083819904, Phase I IUCRC at Purdue University: Center for Bioanalytic Metrology (CBM), G419881185, G42916606, G4410171549, G4501827968, G498139845, G5094606986, G5682117997, G569852198, G6652958823, D3SC: Nonlinear Optical Analysis of Proteins in Glasses, G7354628648, G7905610480, CIF: Medium: Multi-Agent Consensus Equilibrium: Modular Methods for Integrating Disparate Sources of Expertise, G969889393
OpenAlex ID: W4414152733