Multicolor Discrete Frequency Infrared Spectroscopic Imaging.

Advancement of discrete frequency infrared (DFIR) spectroscopic microscopes in image quality and data throughput are critical to their use for analytical measurements. Here, we report the development and characterization of a point scanning instrument with minimal aberrations and capable of diffraction-limited performance across all fingerprint region wavelengths over arbitrarily large samples. The performance of this system is compared to commercial state of the art Fourier transform infrared (FT-IR) imaging systems. We show that for large samples or smaller set of discrete frequencies, point scanning far exceeds (∼10-100 fold) comparable data acquired with FT-IR instruments. Further we show improvements in image quality using refractive lenses that show significantly improved contrast across the spatial frequency bandwidth. Finally, we introduce the ability to image two tunable frequencies simultaneously using a single detector by means of demodulation to further speed up data acquisition and reduce the impact of scattering. Together, the advancements provide significantly better spectral quality and spatial fidelity than current state of the art imaging systems while promising to make spectral scanning even faster.

[1]  Rohit Bhargava,et al.  Using Fourier transform IR spectroscopy to analyze biological materials , 2014, Nature Protocols.

[2]  Rohit Bhargava,et al.  Theory of mid-infrared absorption microspectroscopy: II. Heterogeneous samples. , 2010, Analytical chemistry.

[3]  W. Petrich,et al.  On the role of interference in laser‐based mid‐infrared widefield microspectroscopy , 2018, Journal of biophotonics.

[4]  Rohit Bhargava,et al.  Towards Translation of Discrete Frequency Infrared Spectroscopic Imaging for Digital Histopathology of Clinical Biopsy Samples. , 2016, Analytical chemistry.

[5]  Rohit Bhargava,et al.  Translation of infrared chemical imaging for cardiovascular evaluation , 2016, SPIE BiOS.

[6]  Andre Kajdacsy-Balla,et al.  Simultaneous cancer and tumor microenvironment subtyping using confocal infrared microscopy for all-digital molecular histopathology , 2018, Proceedings of the National Academy of Sciences.

[7]  Rohit Bhargava,et al.  Discrete frequency infrared imaging using quantum cascade lasers for biological tissue analysis , 2016, SPIE BiOS.

[8]  Rohit Bhargava,et al.  Fast Infrared Chemical Imaging with a Quantum Cascade Laser , 2014, Analytical chemistry.

[9]  V. Aksyuk,et al.  Quantitative Chemical Analysis at the Nanoscale Using the Photothermal Induced Resonance Technique. , 2017, Analytical chemistry.

[10]  N. Clarke,et al.  FTIR microscopy of biological cells and tissue: data analysis using resonant Mie scattering (RMieS) EMSC algorithm. , 2012, The Analyst.

[11]  Werner Mäntele,et al.  In vivo noninvasive monitoring of glucose concentration in human epidermis by mid-infrared pulsed photoacoustic spectroscopy. , 2013, Analytical chemistry.

[12]  Delong Zhang,et al.  Depth-resolved mid-infrared photothermal imaging of living cells and organisms with submicrometer spatial resolution , 2016, Science Advances.

[13]  Klaus Gerwert,et al.  Quantum Cascade Laser-Based Infrared Microscopy for Label-Free and Automated Cancer Classification in Tissue Sections , 2018, Scientific reports.

[14]  Federico Capasso,et al.  Multi‐wavelength quantum cascade laser arrays , 2015 .

[15]  M Maarten Steinbuch,et al.  Trajectory planning and feedforward design for electromechanical motion systems , 2005 .

[16]  Rohit Bhargava,et al.  Theory of midinfrared absorption microspectroscopy: I. Homogeneous samples. , 2010, Analytical chemistry.

[17]  R. Bhargava,et al.  Computational Chemical Imaging for Cardiovascular Pathology: Chemical Microscopic Imaging Accurately Determines Cardiac Transplant Rejection , 2015, PloS one.

[18]  F. Capasso,et al.  Quantum cascade lasers with a heterogeneous cascade: Two-wavelength operation , 2001 .

[19]  Rohit Bhargava,et al.  High throughput assessment of cells and tissues: Bayesian classification of spectral metrics from infrared vibrational spectroscopic imaging data. , 2006, Biochimica et biophysica acta.

[20]  Rohit Bhargava,et al.  Discrete frequency infrared microspectroscopy and imaging with a tunable quantum cascade laser. , 2012, Analytical chemistry.

[21]  Y Wang,et al.  Multi-Wavelength Mid-Infrared Micro-Spectral Imaging Using Semiconductor Lasers , 2003, Applied spectroscopy.

[22]  R. Bhargava,et al.  Probe–Sample Interaction-Independent Atomic Force Microscopy–Infrared Spectroscopy: Toward Robust Nanoscale Compositional Mapping , 2018, Analytical chemistry.

[23]  Rohit Bhargava,et al.  Infrared Spectroscopic Imaging Advances as an Analytical Technology for Biomedical Sciences. , 2017, Analytical chemistry.

[24]  Mikhail A. Belkin,et al.  Tip-enhanced infrared nanospectroscopy via molecular expansion force detection , 2014, Nature Photonics.

[25]  Jack L. Koenig,et al.  FTIR Microspectroscopy of Polymeric Systems , 2003 .

[26]  ROHIT BHARGAVA,et al.  Infrared Spectroscopic Imaging: The Next Generation , 2012, Applied spectroscopy.

[27]  Jack L. Koenig,et al.  Comparison of the FT-IR Mapping and Imaging Techniques Applied to Polymeric Systems , 2000 .

[28]  Rémi Carminati,et al.  Theory of infrared nanospectroscopy by photothermal induced resonance , 2010 .