Localized surface plasmon resonance shift and its application in scanning near-field optical microscopy

Abstract

The localized surface plasmon resonance (LSPR) position in tip-enhanced Raman spectroscopy (TERS) is of great importance to the understanding and interpretation of the relative intensity of different enhanced Raman modes. It defines the enhanced spectral range and thus governs the relative intensities of different peaks. Furthermore, it can be exploited to image structural and composition changes through variation in the permittivity of the surrounding medium. In this review, we summarize recent studies on identifying and tuning LSPR position, as well as factors which induce LSPR position shifts in plasmon enhanced scattering techniques, in particular surface- and tip-enhanced Raman scattering (SERS and TERS respectively). Starting with the LSPR properties of single nanoparticles, we then explore the applications of LSPR position shifts in near field mapping.