Spontaneous Raman and Surface-Enhanced Raman Scattering Bioimaging.

Raman spectroscopy is a specific, noninvasive and nondestructive optical technique and is able to obtain chemical information from molecules. Optical imaging based on Raman spectroscopy has been a powerful technique for monitoring minute chemical changes of biological samples and generating images through direct or indirect strategies. Two widely applied Raman imaging techniques include spontaneous Raman and surface-enhanced Raman scattering (SERS) imaging. In this chapter, we introduce the basic principles including the physics behind Raman and SERS imaging, design of Raman/SERS labels or probes, and current strategies for further improvements. The progress in the use of spontaneous Raman and SERS spectroscopy for bioimaging is discussed, either in fundamental studies or in biomedical theranostics. In addition, we give insights into the challenges and opportunities for improving Raman imaging performance.