Trends in Raman chemical imaging

Abstract

The use of Raman microscopy (or Raman chemical imaging) has grown enormously in the last few decades and it has become a valuable tool for a range of applications. Raman microscopy presents several unique features such as ability to provide chemical and spatial information with resolution of a few micrometers in a rapid and non-destructive fashion, requiring little or no sample preparation and the ability to probe aqueous materials. Instrumentation, data processing methods and computer technology advances have made a renaissance of Raman microscopy and the number of applications has continuously growing. Furthermore, other spectroscopic derivatives aimed to improve Raman sensitivity have been recently applied to imaging: coherent anti-Stokes Raman spectroscopy (CARS), stimulated Raman spectroscopy (SRS), surface enhanced Raman spectroscopy (SERS), tip enhanced Raman spectroscopy (TERS) and imaging with carbon nanotubes (CNTs). These methods provide a significant improvement in sensitivity in relation to traditional spontaneous Raman microscopy, allowing faster data acquisition and therefore the study of in-vitro, ex-vivo and in-vivo dynamic systems in an unprecedented manner. This paper will discuss recent papers applying the techniques above mentioned and discuss trends for future Raman chemical imaging.