Tip-enhanced Raman spectroscopy applications: from graphene to heterogeneous catalysis

During the last two decades, tip-enhanced Raman spectroscopy (TERS) has emerged as a promising tool for non-destructive and label-free surface chemical imaging at the nanoscale. TERS is increasingly being used for nanoscale chemical charaterisation in a wide range of applications. Furthermore, tip-enhanced plasmonic near-field can also enhance local photoluminescence (PL) and fluorescence signals to perform tip-enhanced PL (TEPL) and fluorescence (TEFL) microscopy. In this article, we demonstrate the application of TERS to map structural defects within single-layer graphene, application of TEPL microscopy to map defects or contaminants within single-layer MoS2, combination of TERS, TEPL microscopy and photoconductive-atomic force microscopy for simultaneous topographical, chemical and electrical nanoscopy of organic photovoltaic devices and the application of TEFL microscopy to map catalytically active zeolite domains within industrially spent fluid cracking catalyst particles.