Nanoscale investigation of materials, chemical reactions, and biological systems by tip enhanced Raman spectroscopy – a review

Abstract

Almost two decades after the first experimental verification, tip enhanced Raman spectroscopy has developed into a proficient tool of surface characterisation and provides a wealth of chemical and structural information with single molecule sensitivity and nanometric spatial resolution. We recall some highlights of this powerful tool for the investigation of diverse systems to then discuss how the structural arrangement of carbon composites and semiconductor materials has been explored. The advantages of tip enhanced Raman spectroscopy for the study of biological systems, in particular DNA and RNA, will be detailed. We will also present the promise of electrochemical tip enhanced Raman spectroscopy for the real time monitoring of chemical reactions. Eventually, we will discuss the importance of the metallic tip signal, specifically for the imaging of composition and configuration changes in various samples through variations in refractive index or permittivity.