High-resolution infrared imaging in the near and far fields using developing technology

  • Buradsakon Pongtippitak

Student thesis: Phd

Abstract

This thesis presents a comprehensive study on the advancement of high-resolution infrared imaging techniques in the near and far fields, with a particular focus on the development and optimisation of Optical Photothermal Infrared (OPTIR) spectroscopy, a hybrid analytical technique that combines infrared (IR) spectroscopy with optical microscopy to provide high spatial resolution chemical imaging of materials. It detects the photothermal response generated by the absorption of IR light, allowing for the characterisation of chemical compositions at the sub-micron scale. Through detailed experimentation, this research aimed to refine the application of OPTIR spectroscopy for the analysis of PC-3 prostate cancer cells, identifying optimal settings for probe and pump power levels in both low (Quantum Cascade Lasers (QCL)) and high (Optical Parametric Oscillators (OPO)) wavenumber modes to achieve clear and consistent results. The core of this investigation involved a systematic examination of various experimental conditions to determine the most effective configurations for spectroscopic analysis. The study evaluated the clarity of the spectral signal, consistency of results, and the condition of the samples post-experimentation, leading to the identification of conditions that ensured the integrity and reliability of the spectral data, particularly at the Amide I and Amide A peaks. These findings have significant implications for future OPTIR tests, especially in studies focusing on PC-3 prostate cancer cells and potentially other cell types, enhancing the data quality and interpretability in biomedical research. Further, the thesis provides a comprehensive analysis of FTIR spectroscopy and imaging techniques, comparing them with OPTIR spectroscopy to elucidate their distinct spectral outputs and the implications of these differences for scientific research. This comparison highlighted the nuanced deviations in peak positions and spectral quality between the two methods, offering insights into their respective advantages and limitations. In addition to technical optimisation, the thesis explored the impact of omega-3 and omega-6 fatty acid treatments on PC-3 prostate cancer cells under hypoxic conditions. This investigation revealed significant insights into the cellular lipid and protein composition changes, lipid peroxidation mechanisms, and cellular adaptations to oxidative stress, underscoring the complex interplay between nutritional inputs and cellular responses in cancer cells. The application of advanced imaging techniques, such as scanning near-field optical microscopy (s-SNOM), further augmented this research by providing a nanoscale perspective on the topographical and optical properties of cancer cells. Overall, this thesis contributes significantly to the field of infrared imaging, offering valuable methodological advancements and deepening the understanding of cancer cell biology. The findings not only demonstrate the potential of OPTIR and other infrared imaging techniques in scientific research but also highlight the importance of technological innovation in addressing complex biomedical challenges.
Date of Award6 Jan 2025
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorPeter Gardner (Supervisor)

Keywords

  • Fourier Transform Infrared Spectroscopy
  • Optical Photothermal Infrared Spectroscopy
  • PC-3 prostate cancer

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