1
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Kenkel S, Bhargava R. Modeling the Thermoelastic Sample Response for Subdiffraction Infrared Spectroscopic Imaging. CHEMICAL & BIOMEDICAL IMAGING 2024; 2:413-421. [PMID: 38939874 PMCID: PMC11200252 DOI: 10.1021/cbmi.4c00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/18/2024] [Accepted: 04/24/2024] [Indexed: 06/29/2024]
Abstract
There is significant and increasing interest in using the photothermal effect to record infrared (IR) absorption spectra localized to volumes that are considerably smaller than the wavelength of excitation, i.e., subdiffraction imaging. As opposed to conventional IR microscopy, in which absorption and scattering of the illuminating light is measured, subdiffraction imaging can be achieved through detection of the sample's thermal response to IR absorption-induced heating. While this relationship has been examined by a variety of coarse-grained models, a generalized analysis of the dependence of temperature and surface deformation arising from an absorber below the surface has not been reported. Here, we present an analytical model to understand a sample's thermoelastic response in photothermal measurements. The model shows important dependence of the ability to record subdiffraction data on modulation frequency of exciting light, limitations imposed by optical sensing, and the potential to discern location of objects ultimately limited by noise and sharpness of the detecting mechanism. This foundational analysis should allow for better modeling, understanding, and harnessing of the relationship between absorption and sample response that underlies IR photothermal measurements.
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Affiliation(s)
- Seth Kenkel
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Rohit Bhargava
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Departments
of Bioengineering, Mechanical Science and Engineering, Electrical
and Computer Engineering, Chemical and Biomolecular Engineering, and
Chemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Cancer
Center at Illinois, University of Illinois
Urbana−Champaign, Urbana, Illinois 61801, United States
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2
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Dhakal S, Mondal M, Mirzazadeh A, Banerjee S, Ghosh A, Rangachari V. α-Synuclein emulsifies TDP-43 prion-like domain-RNA liquid droplets to promote heterotypic amyloid fibrils. Commun Biol 2023; 6:1227. [PMID: 38052886 PMCID: PMC10697960 DOI: 10.1038/s42003-023-05608-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/17/2023] [Indexed: 12/07/2023] Open
Abstract
Many neurodegenerative diseases including frontotemporal lobar degeneration (FTLD), Lewy body disease (LBD), multiple system atrophy (MSA), etc., show colocalized deposits of TDP-43 and α-synuclein (αS) aggregates. To understand whether these colocalizations are driven by specific molecular interactions between the two proteins, we previously showed that the prion-like C-terminal domain of TDP-43 (TDP-43PrLD) and αS synergistically interact to form neurotoxic heterotypic amyloids in homogeneous buffer conditions. However, it remains unclear if αS can modulate TDP-43 present within liquid droplets and biomolecular condensates called stress granules (SGs). Here, using cell culture and in vitro TDP-43PrLD - RNA liquid droplets as models along with microscopy, nanoscale AFM-IR spectroscopy, and biophysical analyses, we uncover the interactions of αS with phase-separated droplets. We learn that αS acts as a Pickering agent by forming clusters on the surface of TDP-43PrLD - RNA droplets. The aggregates of αS on these clusters emulsify the droplets by nucleating the formation of heterotypic TDP-43PrLD amyloid fibrils, structures of which are distinct from those derived from homogenous solutions. Together, these results reveal an intriguing property of αS to act as a Pickering agent while interacting with SGs and unmask the hitherto unknown role of αS in modulating TDP-43 proteinopathies.
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Affiliation(s)
- Shailendra Dhakal
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
- Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Malay Mondal
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
- Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Azin Mirzazadeh
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
- Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Siddhartha Banerjee
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL, 35401, USA
| | - Ayanjeet Ghosh
- Department of Chemistry and Biochemistry, University of Alabama, Tuscaloosa, AL, 35401, USA
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
- Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
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3
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Yeh K, Sharma I, Falahkheirkhah K, Confer MP, Orr AC, Liu YT, Phal Y, Ho RJ, Mehta M, Bhargava A, Mei W, Cheng G, Cheville JC, Bhargava R. Infrared spectroscopic laser scanning confocal microscopy for whole-slide chemical imaging. Nat Commun 2023; 14:5215. [PMID: 37626026 PMCID: PMC10457288 DOI: 10.1038/s41467-023-40740-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Chemical imaging, especially mid-infrared spectroscopic microscopy, enables label-free biomedical analyses while achieving expansive molecular sensitivity. However, its slow speed and poor image quality impede widespread adoption. We present a microscope that provides high-throughput recording, low noise, and high spatial resolution where the bottom-up design of its optical train facilitates dual-axis galvo laser scanning of a diffraction-limited focal point over large areas using custom, compound, infinity-corrected refractive objectives. We demonstrate whole-slide, speckle-free imaging in ~3 min per discrete wavelength at 10× magnification (2 μm/pixel) and high-resolution capability with its 20× counterpart (1 μm/pixel), both offering spatial quality at theoretical limits while maintaining high signal-to-noise ratios (>100:1). The data quality enables applications of modern machine learning and capabilities not previously feasible - 3D reconstructions using serial sections, comprehensive assessments of whole model organisms, and histological assessments of disease in time comparable to clinical workflows. Distinct from conventional approaches that focus on morphological investigations or immunostaining techniques, this development makes label-free imaging of minimally processed tissue practical.
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Affiliation(s)
- Kevin Yeh
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ishaan Sharma
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Kianoush Falahkheirkhah
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Matthew P Confer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Andres C Orr
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yen-Ting Liu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yamuna Phal
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ruo-Jing Ho
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Manu Mehta
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ankita Bhargava
- University of Illinois Laboratory High School, Urbana, IL, 61801, USA
| | - Wenyan Mei
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, 61802, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Georgina Cheng
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Carle Health, Urbana, IL, 61801, USA
| | - John C Cheville
- Department of Laboratory Medicine and Pathology, College of Medicine and Science, Mayo Clinic, Rochester, MN, 55905, USA
| | - Rohit Bhargava
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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4
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Bhargava R, Yeh K, Kenkel S. High-Fidelity Micro- and Nano-Scale Infrared Spectroscopic Imaging. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:562. [PMID: 37613310 PMCID: PMC11057005 DOI: 10.1093/micmic/ozad067.268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Rohit Bhargava
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Departments of Bioengineering, Chemical and Biomolecular Engineering, Electrical and Computer Engineering, Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- Cancer Center at Illinois, University of Illinois at Urbana- Champaign, Urbana, IL, United States
| | - Kevin Yeh
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Seth Kenkel
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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5
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Bhargava R. Digital Histopathology by Infrared Spectroscopic Imaging. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2023; 16:205-230. [PMID: 37068745 PMCID: PMC10408309 DOI: 10.1146/annurev-anchem-101422-090956] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Infrared (IR) spectroscopic imaging records spatially resolved molecular vibrational spectra, enabling a comprehensive measurement of the chemical makeup and heterogeneity of biological tissues. Combining this novel contrast mechanism in microscopy with the use of artificial intelligence can transform the practice of histopathology, which currently relies largely on human examination of morphologic patterns within stained tissue. First, this review summarizes IR imaging instrumentation especially suited to histopathology, analyses of its performance, and major trends. Second, an overview of data processing methods and application of machine learning is given, with an emphasis on the emerging use of deep learning. Third, a discussion on workflows in pathology is provided, with four categories proposed based on the complexity of methods and the analytical performance needed. Last, a set of guidelines, termed experimental and analytical specifications for spectroscopic imaging in histopathology, are proposed to help standardize the diversity of approaches in this emerging area.
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Affiliation(s)
- Rohit Bhargava
- Department of Bioengineering; Department of Electrical and Computer Engineering; Department of Mechanical Science and Engineering; Department of Chemical and Biomolecular Engineering; Department of Chemistry; Cancer Center at Illinois; and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA;
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6
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Kim D, Grassian VH. Analysis of micro- and nanoscale heterogeneities within environmentally relevant thin films containing biological components, oxyanions and minerals using AFM-PTIR spectroscopy. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:484-495. [PMID: 36789672 DOI: 10.1039/d3em00005b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Minerals in groundwater interact with various chemical and biological species including organic matter, proteins, and prevalent oxyanions, resulting in surface coatings and thin films of these different components. Surface interactions and the surface adsorption of these components on both oxide and oxyhydroxide iron surfaces have been widely investigated using a variety of spectroscopic methods. Despite these numerous studies, there still remains uncertainty with respect to interactions between these individual components, as well as heterogeneities and phase segregations within these thin films. In this study, we investigate mixtures containing Fe-containing minerals, proteins, and oxyanions to better understand surface interactions and phase segregation using Atomic Force Microscopy PhotoThermal Infrared (AFM-PTIR) spectroscopy. The results of this study show that AFM-PTIR spectroscopy can identify both nano- and microscale heterogeneities present within these thin films that are difficult to discern with other more conventional techniques such as ATR-FTIR spectroscopy due to phase segregation and mineral surface interactions. Overall, AFM-PTIR spectroscopy provides insights into multi-component environmental films that are difficult to uncover using other methodologies. This method has the potential to differentiate between bound and unbound toxic species as well as biological components, including environmental DNA, which can be used to assess the fate and transport of these species in the environment.
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Affiliation(s)
- Deborah Kim
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA.
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA.
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7
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Jakob DS, Centrone A. Visible to Mid-IR Spectromicroscopy with Top-Down Illumination and Nanoscale (≈10 nm) Resolution. Anal Chem 2022; 94:15564-15569. [PMID: 36321942 PMCID: PMC9798386 DOI: 10.1021/acs.analchem.2c03685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Photothermal induced resonance (PTIR), an atomic force microscopy (AFM) analogue of IR spectroscopy also known as AFM-IR, is capable of nanoscale lateral resolution and 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 absorption spectra and maps of electronic and vibrational features with spatial resolution down to ≈10 nm. In addition to the improved 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 an optically transparent prism, the top illumination used here greatly simplifies sample preparation and will foster a broad application of this method.
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Affiliation(s)
- Devon S Jakob
- Nanoscale Device Characterization Division, Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Andrea Centrone
- Nanoscale Device Characterization Division, Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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8
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Cosas Fernandes JP, Federico CE, Basterra-Beroiz B, Weydert M, Quintana R. Revealing phase-specific properties of elastomeric blends and their molecular structure at the nanoscale by AFM. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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9
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Schwartz JJ, Jakob DS, Centrone A. A guide to nanoscale IR spectroscopy: resonance enhanced transduction in contact and tapping mode AFM-IR. Chem Soc Rev 2022; 51:5248-5267. [PMID: 35616225 DOI: 10.1039/d2cs00095d] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Infrared (IR) spectroscopy is a broadly applicable, composition sensitive analytical technique. By leveraging the high spatial resolution of atomic force microscopy (AFM), the photothermal effect, and wavelength-tunable lasers, AFM-IR enables IR spectroscopy and imaging with nanoscale (< 10 nm) resolution. The transduction of a sample's photothermal expansion by an AFM probe tip ensures the proportionality between the AFM-IR signal and the sample absorption coefficient, producing images and spectra that are comparable to far-field IR databases and easily interpreted. This convergence of characteristics has spurred robust research efforts to extend AFM-IR capabilities and, in parallel, has enabled AFM-IR to impact numerous fields. In this tutorial review, we present the latest technical breakthroughs in AFM-IR spectroscopy and imaging and discuss its working principles, distinctive characteristics, and best practices for different AFM-IR measurement paradigms. Central to this review, appealing to both expert practitioners and novices alike, is the meticulous understanding of AFM-IR signal transduction, which is essential to take full advantage of AFM-IR capabilities. Here, we critically compile key information and discuss instructive experiments detailing AFM-IR signal transduction and provide guidelines linking experimental parameters to the measurement sensitivity, lateral resolution, and probed depth. Additionally, we provide in-depth tutorials on the most employed AFM-IR variants (resonance-enhanced and tapping mode AFM-IR), discussing technical details and representative applications. Finally, we briefly review recently developed AFM-IR modalities (peak force tapping IR and surface sensitivity mode) and provide insights on the next exciting opportunities and prospects for this fast-growing and evolving field.
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Affiliation(s)
- Jeffrey J Schwartz
- Laboratory for Physical Sciences, College Park, MD 20740, USA.,Nanoscale Device Characterization Division, Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA.
| | - Devon S Jakob
- Nanoscale Device Characterization Division, Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA. .,Institute for Soft Matter Synthesis and Metrology, Georgetown University, 3700 O St., NW Washington D.C., 20057, USA
| | - Andrea Centrone
- Nanoscale Device Characterization Division, Physical Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA.
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10
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Lin YT, He H, Kaya H, Liu H, Ngo D, Smith NJ, Banerjee J, Borhan A, Kim SH. Photothermal Atomic Force Microscopy Coupled with Infrared Spectroscopy (AFM-IR) Analysis of High Extinction Coefficient Materials: A Case Study with Silica and Silicate Glasses. Anal Chem 2022; 94:5231-5239. [PMID: 35312271 DOI: 10.1021/acs.analchem.1c04398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Photothermal atomic force microscopy coupled with infrared spectroscopy (AFM-IR) brings significant value as a spatially resolved surface analysis technique for disordered oxide materials such as glasses, but additional development and fundamental understanding of governing principles is needed to interpret AFM-IR spectra, since the existing theory described for organic materials does not work for materials with high extinction coefficients for infrared (IR) absorption. This paper describes theoretical calculation of a transient temperature profile inside the IR-absorbing material considering IR refraction at the interface as well as IR adsorption and heat transfer inside the sample. This calculation explains the differences in peak positions and amplitudes of AFM-IR spectra from those of specular reflectance and extinction coefficient spectra. It also addresses the information depth of the AFM-IR characterization of bulk materials. AFM-IR applied to silica and silicate glass surfaces has demonstrated novel capability of characterizing subsurface structural changes and surface heterogeneity due to mechanical stresses from physical contacts, as well as chemical alterations manifested in surface layers through aqueous corrosion.
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Affiliation(s)
- Yen-Ting Lin
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Hongtu He
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Key Laboratory of Testing Technology for Manufacturing Process, Ministry of Education, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China
| | - Huseyin Kaya
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Hongshen Liu
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dien Ngo
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Nicholas J Smith
- Science & Technology Division, Corning Incorporated, Corning, New York 14831, United States
| | - Joy Banerjee
- Science & Technology Division, Corning Incorporated, Corning, New York 14831, United States
| | - Ali Borhan
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Seong H Kim
- Department of Chemical Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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11
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V. D. dos Santos AC, Tranchida D, Lendl B, Ramer G. Nanoscale chemical characterization of a post-consumer recycled polyolefin blend using tapping mode AFM-IR. Analyst 2022; 147:3741-3747. [DOI: 10.1039/d2an00823h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tapping mode AFM-IR reveals the presence of contaminants, PP inclusions within the PE phase, and EPR rubber at the interphase between PP and PE in a real-world polyolefin recyclate.
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Affiliation(s)
| | | | - Bernhard Lendl
- Institute of Chemical Technologies and Analytics, TU Wien, 1060 Vienna, Austria
| | - Georg Ramer
- Institute of Chemical Technologies and Analytics, TU Wien, 1060 Vienna, Austria
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12
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Zong H, Yurdakul C, Bai Y, Zhang M, Ünlü MS, Cheng JX. Background-Suppressed High-Throughput Mid-Infrared Photothermal Microscopy via Pupil Engineering. ACS PHOTONICS 2021; 8:3323-3336. [PMID: 35966035 PMCID: PMC9373987 DOI: 10.1021/acsphotonics.1c01197] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mid-infrared photothermal (MIP) microscopy has been a promising label-free chemical imaging technique for functional characterization of specimens owing to its enhanced spatial resolution and high specificity. Recently developed wide-field MIP imaging modalities have drastically improved speed and enabled high-throughput imaging of micron-scale subjects. However, the weakly scattered signal from subwavelength particles becomes indistinguishable from the shot-noise as a consequence of the strong background light, leading to limited sensitivity. Here, we demonstrate background-suppressed chemical fingerprinting at a single nanoparticle level by selectively attenuating the reflected light through pupil engineering in the collection path. Our technique provides over 3 orders of magnitude background suppression by quasi-darkfield illumination in the epi-configuration without sacrificing lateral resolution. We demonstrate 6-fold signal-to-background noise ratio improvement, allowing for simultaneous detection and discrimination of hundreds of nanoparticles across a field of view of 70 μm × 70 μm. A comprehensive theoretical framework for photothermal image formation is provided and experimentally validated with 300 and 500 nm PMMA beads. The versatility and utility of our technique are demonstrated via hyperspectral dark-field MIP imaging of S. aureus and E. coli bacteria and MIP imaging of subcellular lipid droplets inside C. albicans and cancer cells.
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Affiliation(s)
- Haonan Zong
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Celalettin Yurdakul
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Yeran Bai
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Meng Zhang
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - M Selim Ünlü
- Department of Electrical and Computer Engineering and Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Ji-Xin Cheng
- Department of Electrical and Computer Engineering and Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
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13
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Nanomechanical and Chemical Mapping of the Structure and Interfacial Properties in Immiscible Ternary Polymer Systems. CHINESE JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1007/s10118-021-2567-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Liu Y, Lin YT, Haibibu A, Xu W, Zhou Y, Li L, Kim SH, Wang Q. Relaxor Ferroelectric Polymers: Insight into High Electrical Energy Storage Properties from a Molecular Perspective. SMALL SCIENCE 2021. [DOI: 10.1002/smsc.202000061] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Yang Liu
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Yen-Ting Lin
- Department of Chemical Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Aziguli Haibibu
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Wenhan Xu
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Yao Zhou
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Li Li
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Seong H. Kim
- Department of Chemical Engineering The Pennsylvania State University University Park PA 16802 USA
| | - Qing Wang
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
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15
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Siddiquee AM, Houri A, Messalea KA, Lin J, Daeneke T, Abbey B, Mechler A, Kou S. Nanoscale Probing of Cholesterol-Rich Domains in Single Bilayer Dimyristoyl-Phosphocholine Membranes Using Near-Field Spectroscopic Imaging. J Phys Chem Lett 2020; 11:9476-9484. [PMID: 33108191 DOI: 10.1021/acs.jpclett.0c02192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cholesterol is believed to induce the formation of membrane domains, "rafts", which are implicated in a range of natural and pathologic membrane processes. Therefore, it is important to understand the role that cholesterol plays in the formation of these structures. Here, we use label-free spectroscopic imaging to investigate cholesterol fractioning in supported bilayer membranes at nanoscale. Scattering-type scanning near-field optical microscopy (s-SNOM) was used to visualize the formation of cholesterol-induced domains in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes. Our results revealed the coexistence of phase separated domains in DMPC lipids with 10 mol % cholesterol content, whereas a mostly homogeneous bilayer was found at low (5 mol %) and high (15 mol %) cholesterol content. Near-field nano-FTIR spectroscopy was used to identify the cholesterol-rich domains based on their qualitative chemical compositions. It was determined that cholesterol binds to phosphodiester and alkyl glycerol ester moieties, likely via hydrogen bonding of the alcohol to either of the ester oxygens. The results also confirm the existence of an ideal cholesterol-lipid mixture ratio (∼15:85) with a geometrically defined packing. At lower cholesterol content there is phase separation between liquid ordered and almost neat DMPC domains. Thus, the liquid ordered phase exists at an energy minimum at a given lipid-cholesterol ratio.
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Affiliation(s)
- Arif M Siddiquee
- Department of Electronic Science, Fujian Research Center for Solid-State Lighting, Xiamen University, Xiamen 361005, China
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
| | - Aamd Houri
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
| | - Kibret A Messalea
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Jiao Lin
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Torben Daeneke
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Brian Abbey
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
| | - Shanshan Kou
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
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16
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Quaroni L. Imaging and spectroscopy of domains of the cellular membrane by photothermal-induced resonance. Analyst 2020; 145:5940-5950. [PMID: 32706007 DOI: 10.1039/d0an00696c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We use photothermal induced resonance (PTIR) imaging and spectroscopy, in resonant and non-resonant mode, to study the cytoplasmic membrane and surface of intact cells. Non-resonant PTIR images apparently provide rich details of the cell surface. However, we show that non-resonant image contrast does not arise from the infrared absorption of surface molecules and is instead dominated by the mechanics of tip-sample contact. In contrast, spectra and images of the cellular surface can be selectively obtained by tuning the pulsing structure of the laser to restrict thermal wave penetration to the surface layer. Resonant PTIR images reveal surface structures and domains that range in size from about 20 nm to 1 μm and are associated with the cytoplasmic membrane and its proximity. Resonant PTIR spectra of the cell surface are qualitatively comparable to far-field IR spectra and provide the first selective measurement of the IR absorption spectrum of the cellular membrane of an intact cell. In resonant PTIR images, signal intensity, and therefore contrast, can be ascribed to a variety of factors, including mechanical, thermodynamic and spectroscopic properties of the cellular surface. While PTIR images are difficult to interpret in terms of spectroscopic absorption, they are easy to collect and provide unique contrast mechanisms without any exogenous labelling. As such they provide a new paradigm in cellular imaging and membrane biology and can be used to address a range of critical questions, from the nature of membrane lipid domains to the mechanism of pathogen infection of a host cell.
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Affiliation(s)
- Luca Quaroni
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, 30-387, Kraków, Poland.
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17
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Kenkel S, Mittal S, Bhargava R. Closed-loop atomic force microscopy-infrared spectroscopic imaging for nanoscale molecular characterization. Nat Commun 2020; 11:3225. [PMID: 32591515 PMCID: PMC7320136 DOI: 10.1038/s41467-020-17043-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 05/28/2020] [Indexed: 01/15/2023] Open
Abstract
Atomic force microscopy-infrared (AFM-IR) spectroscopic imaging offers non-perturbative, molecular contrast for nanoscale characterization. The need to mitigate measurement artifacts and enhance sensitivity, however, requires narrowly-defined and strict sample preparation protocols. This limits reliable and facile characterization; for example, when using common substrates such as Silicon or glass. Here, we demonstrate a closed-loop (CL) piezo controller design for responsivity-corrected AFM-IR imaging. Instead of the usual mode of recording cantilever deflection driven by sample expansion, the principle of our approach is to maintain a zero amplitude harmonic cantilever deflection by CL control of a subsample piezo. We show that the piezo voltage used to maintain a null deflection provides a reliable measure of the local IR absorption with significantly reduced noise. A complete analytical description of the CL operation and characterization of the controller for achieving robust performance are presented. Accurate measurement of IR absorption of nanothin PMMA films on glass and Silicon validates the robust capability of CL AFM-IR in routine mapping of nanoscale molecular information.
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Affiliation(s)
- Seth Kenkel
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA.,Department of Mechanical Engineering, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - Shachi Mittal
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA
| | - Rohit Bhargava
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA. .,Department of Mechanical Engineering, University of Illinois at Urbana Champaign, Urbana, IL, 61801, USA. .,Cancer Center at Illinois and the Departments Chemical and Biomolecular Engineering, Bioengineering, Electrical and Computer Engineering, and Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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18
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Kurouski D, Dazzi A, Zenobi R, Centrone A. Infrared and Raman chemical imaging and spectroscopy at the nanoscale. Chem Soc Rev 2020; 49:3315-3347. [PMID: 32424384 PMCID: PMC7675782 DOI: 10.1039/c8cs00916c] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The advent of nanotechnology, and the need to understand the chemical composition at the nanoscale, has stimulated the convergence of IR and Raman spectroscopy with scanning probe methods, resulting in new nanospectroscopy paradigms. Here we review two such methods, namely photothermal induced resonance (PTIR), also known as AFM-IR and tip-enhanced Raman spectroscopy (TERS). AFM-IR and TERS fundamentals will be reviewed in detail together with their recent crucial advances. The most recent applications, now spanning across materials science, nanotechnology, biology, medicine, geology, optics, catalysis, art conservation and other fields are also discussed. Even though AFM-IR and TERS have developed independently and have initially targeted different applications, rapid innovation in the last 5 years has pushed the performance of these, in principle spectroscopically complimentary, techniques well beyond initial expectations, thus opening new opportunities for their convergence. Therefore, subtle differences and complementarity will be highlighted together with emerging trends and opportunities.
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Affiliation(s)
- Dmitry Kurouski
- Department Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX 77843, USA.
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19
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Chan KLA, Lekkas I, Frogley MD, Cinque G, Altharawi A, Bello G, Dailey LA. Synchrotron Photothermal Infrared Nanospectroscopy of Drug-Induced Phospholipidosis in Macrophages. Anal Chem 2020; 92:8097-8107. [PMID: 32396367 DOI: 10.1021/acs.analchem.9b05759] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Synchrotron resonance-enhanced infrared atomic force microscopy (RE-AFM-IR) is a near-field photothermal vibrational nanoprobe developed at Diamond Light Source (DLS), capable of measuring mid-infrared absorption spectra with spatial resolution around 100 nm. The present study reports a first application of synchrotron RE-AFM-IR to interrogate biological soft matter at the subcellular level, in this case, on a cellular model of drug-induced phospholipidosis (DIPL). J774A-1 macrophages were exposed to amiodarone (10 μM) or medium for 24 h and chemically fixed. AFM topography maps revealed amiodarone-treated cells with enlarged cytoplasm and very thin regions corresponding to collapsed vesicles. IR maps of the whole cell were analyzed by exploiting the RE-AFM-IR overall signal, i.e., the integrated RE-AFM-IR signal amplitude versus AFM-derived cell thickness, also on lateral resolution around 100 nm. Results show that vibrational band assignment was possible, and all characteristic peaks for lipids, proteins, and DNA/RNA were identified. Both peak ratio and unsupervised chemometric analysis of RE-AFM-IR nanospectra generated from the nuclear and perinuclear regions of untreated and amiodarone-treated cells showed that the perinuclear region (i.e., cytoplasm) of amiodarone-treated cells had significantly elevated band intensities in the regions corresponding to phosphate and carbonyl groups, indicating detection of phospholipid-rich inclusion bodies typical for cells with DIPL. The results of this study are of importance to demonstrate not only the applicability of Synchrotron RE-AFM-IR to soft biological matters with subcellular spatial resolution but also that the spectral information gathered from an individual submicron sample volume enables chemometric identification of treatment and biochemical differences between mammalian cells.
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Affiliation(s)
- Ka Lung Andrew Chan
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Science, King's College London, London SE1 9NH, U.K
| | - Ioannis Lekkas
- Diamond Light Source, Harwell Science and Innovation Campus, Chilton-Didcot OX11 0DE, U.K
| | - Mark D Frogley
- Diamond Light Source, Harwell Science and Innovation Campus, Chilton-Didcot OX11 0DE, U.K
| | - Gianfelice Cinque
- Diamond Light Source, Harwell Science and Innovation Campus, Chilton-Didcot OX11 0DE, U.K
| | - Ali Altharawi
- Institute of Pharmaceutical Sciences, School of Cancer and Pharmaceutical Science, King's College London, London SE1 9NH, U.K
| | - Gianluca Bello
- Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, 1190 Vienna, Austria
| | - Lea Ann Dailey
- Department of Pharmaceutical Technology and Biopharmacy, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
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20
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Nguyen-Tri P, Ghassemi P, Carriere P, Nanda S, Assadi AA, Nguyen DD. Recent Applications of Advanced Atomic Force Microscopy in Polymer Science: A Review. Polymers (Basel) 2020; 12:E1142. [PMID: 32429499 PMCID: PMC7284686 DOI: 10.3390/polym12051142] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/26/2022] Open
Abstract
Atomic force microscopy (AFM) has been extensively used for the nanoscale characterization of polymeric materials. The coupling of AFM with infrared spectroscope (AFM-IR) provides another advantage to the chemical analyses and thus helps to shed light upon the study of polymers. This paper reviews some recent progress in the application of AFM and AFM-IR in polymer science. We describe the principle of AFM-IR and the recent improvements to enhance its resolution. We also discuss the latest progress in the use of AFM-IR as a super-resolution correlated scanned-probe infrared spectroscopy for the chemical characterization of polymer materials dealing with polymer composites, polymer blends, multilayers, and biopolymers. To highlight the advantages of AFM-IR, we report several results in studying the crystallization of both miscible and immiscible blends as well as polymer aging. Finally, we demonstrate how this novel technique can be used to determine phase separation, spherulitic structure, and crystallization mechanisms at nanoscales, which has never been achieved before. The review also discusses future trends in the use of AFM-IR in polymer materials, especially in polymer thin film investigation.
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Affiliation(s)
- Phuong Nguyen-Tri
- Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC G8Z 4M3, Canada;
| | - Payman Ghassemi
- Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières (UQTR), Trois-Rivières, QC G8Z 4M3, Canada;
| | - Pascal Carriere
- Laboratoire MAPIEM (EA 4323), Matériaux Polymères Interfaces Environnement Marin, Université de Toulon, CEDEX 9, 83041 Toulon, France;
| | - Sonil Nanda
- Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A2, Canada;
| | - Aymen Amine Assadi
- ENSCR—Institut des Sciences Chimiques de Rennes (ISCR)—UMR CNRS 6226, Univ Rennes, 35700 Rennes, France;
| | - Dinh Duc Nguyen
- Faculty of Environmental and Food Engineering, Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, District 4, Ho Chi Minh City 755414, Vietnam;
- Department of Environmental Energy Engineering, Kyonggi University, Suwon 16227, Korea
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21
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Khanal D, Chang RYK, Morales S, Chan HK, Chrzanowski W. High Resolution Nanoscale Probing of Bacteriophages in an Inhalable Dry Powder Formulation for Pulmonary Infections. Anal Chem 2019; 91:12760-12767. [DOI: 10.1021/acs.analchem.9b02282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Dipesh Khanal
- Advanced Drug Delivery Group, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Sydney Nano Institute, Faculty of Medicine and Health, Sydney Pharmacy School, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rachel Yoon Kyung Chang
- Advanced Drug Delivery Group, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia
| | - Sandra Morales
- AmpliPhi Biosciences AU, Brookvale, Sydney, NSW 2001, Australia
| | - Hak-Kim Chan
- Advanced Drug Delivery Group, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia
| | - Wojciech Chrzanowski
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia
- Sydney Nano Institute, Faculty of Medicine and Health, Sydney Pharmacy School, The University of Sydney, Sydney, New South Wales 2006, Australia
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22
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Watts KE, Blackburn TJ, Pemberton JE. Optical Spectroscopy of Surfaces, Interfaces, and Thin Films: A Status Report. Anal Chem 2019; 91:4235-4265. [PMID: 30790520 DOI: 10.1021/acs.analchem.9b00735] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kristen E Watts
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
| | - Thomas J Blackburn
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
| | - Jeanne E Pemberton
- Department of Chemistry and Biochemistry University of Arizona 1306 East University Boulevard , Tucson , Arizona 85721 , United States
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23
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Abstract
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.
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Affiliation(s)
- Kevin Yeh
- Department of Bioengineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 4265 Beckman Institute, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Dongkwan Lee
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 4265 Beckman Institute, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Rohit Bhargava
- Department of Bioengineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
- Departments of Mechanical Science and Engineering, Electrical and Computer Engineering, and Chemistry, Cancer Center at Illinois, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 4265 Beckman Institute, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
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24
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Smith CI, Siggel-King MRF, Ingham J, Harrison P, Martin DS, Varro A, Pritchard DM, Surman M, Barrett S, Weightman P. Application of a quantum cascade laser aperture scanning near-field optical microscope to the study of a cancer cell. Analyst 2019; 143:5912-5917. [PMID: 30191233 DOI: 10.1039/c8an01183d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This work reports the first images obtained by combining an infrared aperture scanning near-field optical microscope (SNOM) with a quantum cascade laser (QCL). The future potential of this set-up is demonstrated by a preliminary study on an OE33 human oesophageal adenocarcinoma cell in which the cell is imaged at 1751 cm-1, 1651 cm-1, 1539 cm-1 and 1242 cm-1. In addition to the 1651 cm-1 image, three other images were acquired within the Amide I band (1689 cm-1, 1675 cm-1 and 1626 cm-1) chosen to correspond to secondary structures of proteins. The four images obtained within the Amide I band show distinct differences demonstrating the potential of this approach to reveal subtle changes in the chemical composition of a cell.
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Affiliation(s)
- Caroline I Smith
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, UK.
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25
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Isensee K, Kröger-Lui N, Petrich W. Biomedical applications of mid-infrared quantum cascade lasers - a review. Analyst 2019; 143:5888-5911. [PMID: 30444222 DOI: 10.1039/c8an01306c] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mid-infrared spectroscopy has been applied to research in biology and medicine for more than 20 years and conceivable applications have been identified. More recently, these applications have been shown to benefit from the use of quantum cascade lasers due to their specific properties, namely high spectral power density, small beam parameter product, narrow emission spectrum and, if needed, tuning capabilities. This review provides an overview of the achievements and illustrates some applications which benefit from the key characteristics of quantum cascade laser-based mid-infrared spectroscopy using examples such as breath analysis, the investigation of serum, non-invasive glucose monitoring in bulk tissue and the combination of spectroscopy and microscopy of tissue thin sections for rapid histopathology.
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Affiliation(s)
- Katharina Isensee
- Kirchhoff-Institute for Physics, Heidelberg University, INF 277, 69120 Heidelberg, Germany.
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