Imaging Based Raman Spectroscopy

Raman Spectroscopy has been widely explored as a label-free, non-invasive, and non-destructive tool in different areas of biomedical research. In recent years, there have been significant advancements in imaging-based Raman spectroscopy methods. This has opened up new doors for diversified applications of this method in various aspects of biomedical sciences. Raman images are made up of pixels with full-range Raman spectra. Such images offer a wealth of information regarding the chemical and biochemical composition of the specimen in a label-free manner. The pseudo-colour images generated via intensity mapping or by the clustering of similar Raman spectra can provide information about the distribution of a specific chemical species, structural integrity, biomarkers, and early changes associated with disease onset. Laced with attributes such as high sensitivity/specificity, minimal sample processing, and objectivity, Raman imaging has become a highly sought-after analytical technique. The present chapter provides details about the basics of various Raman imaging methods with suitable examples from biomedical applications. The chapter covers spontaneous imaging, imaging with Surface-enhanced Raman scattering (SERS) or tip-enhanced Raman scattering (TERS), imaging with Coherent anti-Stokes Raman scattering (CARS) and imaging with carbon nanotubes.