Applications of SERS Sensing to Biomedicine and Biomolecules

Abstract

Raman scattering from molecules adsorbed on noble metal surface is enormously enhanced. This phenomenon is called as surface-enhanced Raman scattering (SERS). It has recently been applied to extensively biomedical fields. In this chapter, biomedical sensing for bacteria and biomolecules by SERS are introduced. For bacteria different molecules have been separately measured from chemical and photo reduced noble metal nanoparticles (NPs) at extracellular or intracellular locations. Various molecules of cell measured by SERS indicate the metabolism and classify the bacteria to strain level via chemometrics. Moreover, SERS imaging, which show molecular distributions, of a living cell have been observed by the metal NPs without and with reporter molecule. For also biomolecules, the NPs without and with reporter molecule have been applied to SERS sensor. By using the bare metal NPs, spin and oxidation state of hemeprotein can be hardly discriminated via shifts of the marker bands. On the other hand, non-metal SERS substrates due to the charge transfer mechanism has been developed. By using the NPs labeled with achiral molecule, chiral molecules have been discriminated via the charge transfer mechanism. By the NPs labeled with dye, moreover, spectral multiplex of biomolecules has been succeeded via aggregation through the analyte. Finally, it is introduced that biomarkers for cancer have been detected by SERS.