Ryo Kato
Specially Appointed Assistant Professor
Tokushima University Post-LED Photonics Research Institute
Raman spectroscopy allows us to directly fetch information regarding chemical properties of molecules. It is difficult to observe properties of materials at nanoscale.
Tip-enhanced Raman spectroscopy (TERS) that combines Scanning Probe Microscopy (SPM) with Raman Spectroscopy, is a powerful analytical technique for revealing both the topographic and chemical properties of materials at the nanometer scale. light is confined and enhanced in the vicinity of the apex of a metallic nano-tip owing to localized surface plasmons, TERS provides high spatial resolution far beyond the diffraction limit of light and high sensitivity, both of which nowadays reaches down to single molecule level.
TERS allows us to not only map the chemical compositions of samples, but also observe unique physical properties, such as van der Waals interactions and defects in a sample at nano-meter scale. , such as nano-carbon materials, 2D-materials, and biological samples.
Stable TERS system
for long-duration TERS imaging
Although TERS was invented more than 20 years ago, there are still challenges for reproducible and reliable TERS measurement. I have been interested in instrumentation of TERS, such as facile and reproducible fabrication of TERS probe tips, theoretical calculation of near-field Raman scattering intensity and optical setup to compensate thermal drift of AFM to stabilize TERS system and realize long-term hyperspectral TERS imaging of sensitive 2D materials.
Other on-going projects are highly sensitive bio-sensing at the single molecule level with plasmonic metal nanostructures or metamaterials that confine optical fields at the nanometer scale and drastically enhance the fields, and infrared spectroscopy and imaging using mid-infrared photothermal microscopy for biochemical applications.
I aim at providing new insight of biological functions and phenomena from single molecule to cell level.
