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Exploring the nanoworld using surface
enhanced spectroscopy

YAMAMOTO Lab.
Associate Professor:YAMAMOTO Yuko S.

E-mail:
[Research areas]surface enhanced spectroscopy, quantum optics, catalysts
[Keywords]Spectroscopy, Raman spectroscopy, surface enhanced spectroscopy, surface-enhanced Raman scattering (SERS), tip-enhanced Raman scattering, nanomaterials

Skills and background we are looking for in prospective students

“I love research activity!” “I enjoy scientific experiments!” “I love creating new materials!” “I want to improve the world with my great discovery!” At least one of these should apply to you because such motivations are essential for starting researches in our lab. I teach you the knowledge necessary to make achievements and the method of learning new techniques. Students with grand ambitions are particularly welcome.

What you can expect to learn in this laboratory

The ability to open new horizons through your own efforts. This skill is of use in many areas of our life, but there are few opportunities to learn it. I recommend you to have several skills in our lab: (1) sensitively perceive the present situation to forge your own path to new possibilities, (2) an appropriate awareness of the present issues and possess the solving skills of these issues, (3) a high level of linguistic ability, including presentation skills, communication skills, and written composition skills, (4) strong interpersonal skills to obtain funding and build consensus. I support you as you learn these through advancing your research. I also support you in studying abroad or starting a venture business during or after your time in our laboratory.

【Job category of graduates】
Chemistry manufacturers, start-ups, etc.

Research outline

What actually happens in the world at a nanometer scale? We explore the “nanoworld” using surface-enhanced spectroscopy. Generally speaking, spectroscopy makes us possible to obtain the chemical composition of measuring targets with irradiating the laser light or other light sources and careful analysis of the absorption, reflection and scattering of light. Surface-enhanced spectroscopy is a technique of dramatically increasing the intensity of the absorption, reflection and scattering of light using the surface of nanostructures which composed of free electron-rich metals such as silver or gold. This phenomenon enables us to measure the chemical composition of measuring targets at a very small scale – nanometer-order.
In our lab, we constructed an original surface-enhanced spectroscopic system which enable to measure even single molecule, so we believe there are great expectations from the aspects of both research and industrial applications.


Figure. Schematic of surface-enhanced Raman scattering measurement.

Based on "surface-enhanced Raman spectroscopy", one of the surface-enhancement spectroscopy, we can obtain the information on the vibration level of molecules.
Our lab promotes both fundamental researches and applied researches. Current research topics of us are as follows:

1.Surface analysis of catalytic chemical reactions using surface-enhanced Raman scattering

In recent years, nanostructures made of coinage metals such as gold and silver, showing strong plasmon resonance in the visible light region are considered very promising as next-generation heterogeneous photocatalyst materials. A conventional heterogeneous photocatalysts such as titanium dioxide (TiO2), which is well-known for its Honda-Fujishima effect, requires ultraviolet light to produce the catalytic effect. Meanwhile, chemical reactions such as water splitting(2H2O→2H2+O2) and dissociation of hydrogen molecules (H2→H+H), which had conventionally been considered to require the energy of ultraviolet light, have been realized with the visible light using a new heterogeneous photocatalyst discovered in the early 2010s, and this research is progressing globally to investigate the new phenomenon of such heterogeneous photocatalysts.
In our lab, we focus on the photochemical reactions which occur on a surface of metal nanoparticles with plasmon resonance, monitored by surface-enhanced Raman scattering with irradiation of visible light.

2.Looking ahead to surface-enhanced Raman scattering

About 50 years have passed since the surface-enhanced Raman scattering effect was discovered in the 1970s. Although the mechanism of the surface-enhanced Raman scattering phenomena is becoming increasingly deeply understood, there are mysteries that still remain. Our lab focuses on these mysteries and explores the most advanced areas of surface-enhanced Raman scattering. At the same time, we are working to discover new physical or chemical phenomena that emerge from surface-enhanced Raman scattering and understand their mechanisms.
If you would like to see references or papers on research results, please feel free to email to Yamamoto () or visit Yamamoto’s office. I will give you copies of our papers.

Key publications

  1. Judith Langer, Yuko S. Yamamoto et al, “Present and Future of Surface Enhanced Raman Scattering”, ACS Nano, 14, 28-117, 2020.
  2. Yuko S. Yamamoto*, Yuya Kayano, Yukihiro Ozaki et al, “Single-Molecule Surface-Enhanced Raman Scattering Spectrum of Non-Resonant Aromatic Amine Showing Raman Forbidden Bands”, arXiv:1610.08270, 2016.
  3. Yuko S. Yamamoto*, Tamitake Itoh*, “Why and how do the shapes of surface-enhanced Raman scattering spectra change? Recent progress from mechanistic studies”, J. Raman Spectrosc., 47, 78-88, 2016.

Equipment

Surface-enhanced Raman microscope (homemade)
Density functional theory (DFT) calculation system

Teaching policy

I have personally studied what kind of environment is suitable for the basic research. As a result, I found that a free and unfettered research environment is the best for effective basic research. Therefore, our laboratory basically does not have a core time. Information exchanges with members in our lab and confirmation of progress with peers are conducted in the weekly general meeting and seminars. I encourage students to come our lab who can autonomously manage their own research activities properly.
I recommend all the students in our lab to make presentations in domestic/international conferences about once a year to express our research results to the world. To the best of my skills, research themes of students are established taking into consideration the range and direction of each students' interests and according to their preferences, with consideration of the research theme presented by me. Basically, we aim to publish our research results in the international journals.
Of course, I always provide individual guidance for each students as needed. Students are encouraged to actively make use of my knowledge and experiences.

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