Tip-enhanced Raman spectroscopy (TERS) is a powerful tool for gaining detailed and high-resolution insights into the world of molecules. This technology makes it possible to analyze the molecular composition and structure of surfaces at the nanometer level. Researchers from the Leibniz Institute of Photonic Technology (Leibniz IPHT) in Jena, Germany, and an international team have published an introduction to the theoretical background, the required technique and the potential of this technology for life and material sciences and disease research in the renowned journal Nature Reviews Methods Primers.

TERS enables chemical imaging of surfaces with submolecular resolution. The technique combines the chemical sensitivity of Raman spectroscopy with significant signal enhancement from localized optical fields at a plasmonically active, nanometer-thin gold or silver tip. In combination with atomic force microscopy (AFM), non-destructive chemical information can be obtained far below the resolution of optical microscopes, which is relevant for many applications in life sciences and medicine.

Molecular Structures well below the Diffraction Limit

In their article, Prof. Volker Deckert and Dr. Christiane Höppener from Leibniz IPHT and the University of Jena emphasize that the applications of TERS range from genetic research to materials science. In the life sciences and medicine in particular, this opens up opportunities for research into diseases and therapies. “TERS enables the detection of molecular structures far below the diffraction limit without the need for labels,” explains Prof. Deckert, who has received several international awards for his work in the field of Raman spectroscopy.

Insights into the Chemical Differences of Viruses

In Jena, Deckert and his team are researching a method for the rapid and direct identification of influenza or SARS-CoV-2 viruses using TERS. Together with PD Dr. Stefanie Deinhardt-Emmer from Jena University Hospital, they are developing methods for the early detection of viral epidemics in the SARS-CoV-2Dx collaborative project and are demonstrating how TERS can be used to rapidly characterize the surface of viruses and detect the smallest differences between proteins and lipids on the surface of the virus.

Nanoparticles Transport Drugs in the Body

Dr. Christiane Höppener is using TERS and AFM to investigate the chemical and nanomechanical properties of polymer nanoparticles in the Collaborative Research Center Polytarget at the Friedrich Schiller University of Jena. The aim is to improve their efficacy as carrier materials for the treatment of inflammatory diseases. Researchers at the CRC are developing tailor-made polymer nanoparticles in which drugs can be packaged and targeted to their site of action in the body.

Direct Observation of Catalysts

Another application of TERS is the direct study of catalyst surfaces. Thanks to the high resolution of TERS, local differences in the reactivity of catalysts can be made visible. This detailed information helps to improve catalysts and increase their efficiency.

 

Original Article in Nature Reviews Methods Primers:

Höppener, C.; Aizpurua, J.; Chen, H.; Gräfe, S.; Jorio, A.; Kupfer, S.; Zhang, Z.; Deckert V., Tip-enhanced Raman scattering. Nat Rev Methods Primers 4, 47 (2024). https://doi.org/10.1038/s43586-024-00323-5