ABSTRACT

This chapter provides detailed information of the state-of-the-art in tip-enhanced Raman spectroscopy. It focuses on its application to induce chemical reactions through plasmonics as well as probing biological processes with enhanced spectroscopy methods. Surface plasmons excited on metal nanostructures have been used to initiate chemical reactions, which are so-called plasmon driven/catalyzed chemical reactions, where the plasmonic nanostructure acts as the catalytic active site. The hot electrons, generated from plasmon decay, work as a main catalyst in plasmon driven/catalyzed chemical reactions. Generation of hot electrons and the respective transfer behavior are crucial for understanding hot electron chemistry applications and achieving practically useful efficiency. Surface plasmons generally decay by either emitting a photon (radiative) or generating an electron-hole pair (non-radiative) through Landau damping. Hot electrons arising from surface plasmon decay have a kinetic energy high enough to overcome the reaction activation barrier and can be directly transferred to an unoccupied energy level in the adjacent electron acceptor.