Mar 27 2019
Researchers from the National Physical Laboratory (NPL) and Utrecht University have formed a strong protocol for nanoscale chemical imaging with the help of tip-enhanced Raman spectroscopy (TERS), as reported in the journal Nature Protocols.
Chemical imaging of surfaces is vital to understand the associations between chemical, structural, and functional properties in domains spanning across the material, chemical, and biological sciences. Traditional techniques of chemical analysis are generally limited by drawbacks of microscale spatial resolution, low sensitivity, high vacuum, inappropriate labeling, and destruction of the samples under investigation.
Researchers from NPL and Utrecht University have shown the potential of a new analytical method known as tip-enhanced Raman spectroscopy (TERS), which overcomes the drawbacks of traditional analytical techniques and offers label-free and non-destructive chemical imaging at the nanoscale, in air as well as liquid environments. In order to employ this technique more extensively, many practical difficulties had to be overcome and a strong process had to be developed to enable reproducible and conclusive results.
This was achieved over the course of many years, and presently, the researchers can successfully employ TERS to characterize self-assembled monolayers of organic molecules, single-wall carbon nanotubes, polymer thin-films, nanoscale structural defects in single-layer graphene, small molecules in biological cells, and reactions in heterogeneous catalytic systems.
With a consistent technology in place, TERS can now be used in new application areas as well, principally in areas where imaging of surfaces in liquid is needed, which has not been possible to date. Since TERS offers basic insights into the chemical behavior of materials, this insight will allow new products to be made at a faster rate, in a range of technological areas worth billions of dollars.
Over the last two decades, TERS has emerged as a powerful and reliable tool for surface chemical characterization at the nanoscale, combining the high chemical sensitivity of surface-enhanced Raman spectroscopy (SERS) and nanoscale spatial resolution of scanning probe microscopy (SPM). The publication of this protocol will enable the further acceleration of TERS research around the world, and help researchers to obtain robust analytical data on a wide variety of functional materials.
Dr Naresh Kumar, Study Lead Author and Research Scientist, NPL
Measuring catalytic events at the nanometre scale is very challenging. This is necessary to develop new or much improved catalytic materials to accelerate chemical processes, thereby fostering the transition towards a more sustainable society. TERS is one of the promising techniques and the reported measurement protocols in this article will help scientists to uncover the intricacies of catalytic processes.
Bert Weckhuysen, Professor of Inorganic Chemistry and Catalysis, Utrecht University