A Life of Spectroscopic Exploration: An Interview with Professor Yukihiro Ozaki, Recipient of the 2025 Ellis R. Lippincott Award

Prof. Yukihiro Ozaki, the recipient of the 2025 Ellis R. Lippincott Award from Optica, the Society for Applied Spectroscopy (SAS), and the Coblentz Society (1,2), has made many contributions to vibrational spectroscopy, spanning Raman (3), resonance Raman (4), surface-enhanced Raman (SERS) (5-10), near-infrared (NIR) (11-13), and far-infrared (FIR)/terahertz spectroscopy (14). He has also been involved in far-ultraviolet (FUV) spectroscopy (15) and various spectral analysis methods such as quantum chemical calculation (16,17), chemometrics (18), and two-dimensional correlation (2D-COS) spectroscopy (19). With a career spanning over four decades, Ozaki has been a driving force in advancing both the fundamental understanding and practical applications of these techniques in fields ranging from materials sciences including nanomaterials, food science, and biomedical sciences. His research output includes over 1,120 publications, 70 reviews and book chapters, and 19 co-authored or edited books. In this interview, Ozaki reflects on his career, the significance of receiving the Lippincott Award, his most challenging and rewarding research experiences, and his vision for the future of vibrational spectroscopy. He also offers advice to young scientists aspiring to follow in his footsteps in this ever-advancing field of science.

Congratulations on receiving the Ellis R. Lippincott Award! What does this recognition mean to you personally and professionally, given its emphasis on innovation in vibrational spectroscopy?

I started my career as a Raman spectroscopist in the early 70s, more than 50 years ago. At that time Raman spectroscopy was a rather difficult technique; one needed a lot of patience and effort to work on it.Almost every day I fought with fluorescence from biological materials and molecules. For the last 50 years or so Raman spectroscopy has made marvelous progress year by year and become a dream spectroscopy. One can use it almost excitingly for various materials and various purposes. Interesting enough, the Lippincott Award was born in 1975, exactly 50 years ago. Therefore, the present recognition means that I have developed my vibrational spectroscopy studies for a half century along with remarkable development of vibrational spectroscopy.

You have made significant contributions to Raman spectroscopy, particularly in its applications to nanomaterials and biological systems. What do you see as the most transformative advancements in Raman spectroscopy during your career?

I have two transformative advancements in Raman spectroscopy during my career. One is concerned with medical application of Raman spectroscopy, and another is concerned with surface-enhanced Raman spectroscopy (SERS). I may be the first to utilize Raman spectroscopy to explore the progress of disease (3). In 1982, which is more than 40 years ago, I succeeded in monitoring nondestructively changes in water in a lens and the structural changes of tyrosine and cysteine residues of lens proteins during the development of mouse diabetic cataract. This success ignited medical application of Raman spectroscopy (3). Another of my important contributions to Raman spectroscopy is to develop SERS (5-10). I have been involved in the studies of the mechanism of SERS and semiconductor-enhanced Raman spectroscopy (5). I have also been involved in the applications of SERS and TERS (5,7-10), for example, SERS for protein detection, three-dimensional SERS imaging, chiral discrimination by SERS and TERS, and TERS with a chemically modified TERS tip.

Resonance Raman has been a key area of your work. What are some of the most exciting applications you have explored, and how do you see this technique changing in the future?

Yes, resonance Raman spectroscopy has been one of the key areas of my work. My PhD thesis was resonance Raman studies of hemeproteins and porphyrins. My unique resonance Raman studies were nondestructive analysis of photosynthetic bacteria and foods. An interesting example was that I investigated the formation of J- and H-aggregates of lycopene and their imaging in vivo in tomato using resonance Raman spectroscopy. This was a tomato study, but its paper was published in J. Phys. Chem. B. I also found that even 1064 nm excitation gave resonance Raman spectra of carotenoids in photosynthetic bacteria in situ. Very modern our exciting resonance Raman study is a study of N‑acetylamino saccharides with synchrotron-based ultraviolet resonance Raman spectroscopy: in combination with ATR FUV spectroscopy (4).Resonance Raman spectroscopy is a very general method ranging from deep UV excitation to NIR excitation. It is also involved in SERS as surface-enhanced resonance Raman spectroscopy. FUV excited resonance Raman should be attractive, and synchrotron-based ultraviolet resonance Raman spectroscopy is a promising technique. There is room for theoretical investigations of resonance Raman spectroscopy to be developed more.

You have been instrumental in advancing near-infrared spectroscopy, from fundamental studies to applications in materials science, food science, process analysis, and biomedicine. What do you consider your most impactful contribution to the NIR field?

My most impactful contributions to the NIR fieldwere fundamental studies of NIR spectroscopy (11-13), studies of overtones, combination modes, and anharmonicity, and those of spectral analysis methods such as chemometrics (18), two-dimensional correlation spectroscopy (19), and anharmonic quantum chemical calculations (16,17).

Your research on surface-enhanced Raman scattering (SERS) has led to important insights into its mechanisms and applications. What challenges remain in fully harnessing SERS for real-world applications?

I think there are three points. 1) further development of the studies of the mechanism of SERS and semiconductor-enhanced Raman scattering. Both electromagnetic enhancement and chemical enhancement (5). 2) Developments of SERS substrates and metal particles (10). 3) Development of spectral analysis methods including machine learning and AI (10).

Your research spans a broad spectral range, including far-ultraviolet (FUV) spectroscopy. What unique advantages does FUV spectroscopy offer, and how do you see it complementing vibrational spectroscopic techniques?

From the point of basic science, the most important advantage of ATR-FUV spectroscopy is that one can explore σ chemistry using FUV spectroscopy (15). The electronic structure and reactions of σ bonds in molecules may be investigated by ATR-FUV spectroscopy. Investigations of Rydberg states and transitions are also important targets. From the points of applications one can use ATR-FUV as an ultrathin surface (10-30 µm) analytical technique (15). ATR-FUV spectroscopy has been applied to explore the electronic structure of simple molecules such as water and alcohols, polymers, inorganic materials, ion liquids,nanomaterials, and biological materials (15). ATR-FUV plasmon resonance is also promising. Good example of a combined study of FUV spectroscopy and vibrational spectroscopy is a study of N‑acetylamino saccharides with synchrotron-based ultraviolet resonance Raman spectroscopy: in combination with ATR FUV spectroscopy, as I mentioned above in the previous question. One can investigate hydrogen bondings from different points of view using FUV and vibrational spectroscopy. For example, when one investigates water, one sees electrons on an oxygen atom by FUV spectroscopy while observing O-H bonds by vibrational spectroscopy. Therefore, by combining ATR-FUV spectroscopy and vibrational spectroscopy, it is possible to have a nicer picture of hydrogen bondings.

You have played a significant role in the development and application of 2D-COS. How has this method advanced the interpretation of complex spectroscopic data, and what are its most promising future applications?

The application fields of 2D-COS are broad (19). 2D-COS can be applied to any kind of spectroscopy and any kind of materials. Asynchronous spectra play a unique role in the interpretation of complex spectroscopic data. However, a serious problem in 2D-COS is baseline fluctuations of raw spectra data, which cause strange peaks in asynchronous spectra. I think the further development of spectra pretreatment methods is very important for 2D-COS. This should enable further development of the application of 2D-COS. Moreover, one should use more hetero correlation 2D-COS.

Chemometric techniques have been essential in analyzing complex spectral data. What are some of the most significant advances in chemometrics that have influenced your research?

Since 2001 advances in chemometrics were little by little for my research. The most important advance in chemometrics for our research is our proposal of applying the moving window PLS method (MWPLS) (18). This is really powerful and useful for various spectroscopies.

Looking back on your extensive career, which research project or discovery has been the most personally satisfying for you?

Very difficult to select one. I have selected the following three points. 1) Success in monitoring the process of cataract development in situ by Raman spectroscopy. 2) We bought an FT-Raman instrument in 1992 and found that this could be used as an FT-NIR spectrometer. I think we may be one of the first to start using FT-NIR spectroscopy. 3) Establishment of ATR-FUV spectroscopy.

What has been the most difficult scientific challenge you have faced in your career, and how did you overcome it?

The most difficult scientific challenge I have faced in my career was Raman measurements of organs and tumors in 1980s. We overcome these problems using FT-Raman spectroscopy in 1993. We succeeded in obtaining beautiful Raman spectra of human brain tissues. Nowadays people use NIR excited dispersive Raman systems to avoid fluorescence.

What advice would you give to young researchers who are interested in pursuing a career in vibrational spectroscopy?

Do not stick to past studies or subjects! Travel the world in search of something new! Propose your own spectroscopy that adheres to the existing spectroscopies. Consider applications based on new concepts, such as health science, disaster science, and sensory science, quality technology. The combination of existing spectroscopies may have the potential to create something new, like the combination of FUV and UVRR that we have conducted. In science, serendipity is the most important.

Although you have officially retired, you remain highly active in research. What are your current research interests, and what areas of spectroscopy do you see yourself focusing on in the coming years?

Currently, I am interested in 1) water structure research using IR, NIR and Raman spectroscopy together with 2D-COS and conventional spectral analysis methods. 2) Studies of mechanism and applications of SERS particularly in semiconductor-enhanced Raman spectroscopy. 3) FUV-UVRR studies; and spectral analysis and applications. 4) Applications and spectral analysis of low-frequency vibrational spectroscopy (FIR and low-frequency Raman).

References and Further Reading

(1) Optica. Ellis R. Lippincott Award Page. https://www.optica.org/get_involved/awards_and_honors/awards/award_descriptions/ellislippincott/ (accessed 2025-03-14).

(2) Workman, J., Jr. Ellis Ridgeway Lippincott: A Legacy of Scientific Innovation. Spectroscopy2024, 39 (5), 40–44. DOI: 10.56530/spectroscopy.ky8184w3

(3) Sato, H.; Popp, J.; Wood, B.; Ozaki, Y., Eds. Raman Spectroscopy in Human Health and Biomedicine; World Scientific, 2023.

(4) Hashimoto, K.; Matroodi, F.; Morimatsu, S.; Rossi, B.; Morisawa, Y.; Ozaki, Y.; Sato, H. Study of N‑Acetylamino Saccharides with Synchrotron-Based Ultraviolet Resonance Raman Spectroscopy: In Combination with ATR Far-Ultraviolet Spectroscopy. J. Phys. Chem. Lett.2025, 16, 1769−1777. DOI: 10.1021/acs.jpclett.4c03435

(5) Itoh, T.; Procházka, M.; Dong, Z. C.; Ji, W.; Yamamoto, Y. S.; Zhang, Y.; Ozaki, Y. Toward a New Era of SERS and TERS at the Nanometer Scale: From Fundamentals to Innovative Applications. Chem. Rev.2023, 123, 1552–1634. DOI: 10.1021/acs.chemrev.2c00316.

(6) Yi, J.; et al. Surface-Enhanced Raman Spectroscopy: A Half-Century Historical Perspective. Chem. Soc. Rev.2025, 54, 1453–1551. DOI: 10.1039/d4cs00883a

(7) Han, X. X.; Zhao, B.; Ozaki, Y. Surface-Enhanced Raman Scattering for Protein Detection. Anal. Bioanal. Chem.2009, 394, 1719–1727. DOI: 10.1007/s00216-009-2702-3

(8) Han, X. X.; Rodriguez, R. S.; Haynes, C. L.; Ozaki, Y.; Zhao, B. Surface-Enhanced Raman Spectroscopy. Nat. Rev. Methods Prim.2022, 1, 87. DOI: 10.1038/s43586-021-00083-6

(9) Langer, J.; et al. Present and Future of Surface-Enhanced Raman Scattering. ACS Nano2019, 14, 28–117. DOI: 10.1021/acsnano.9b04224

(10) Procházka, M.; Kneipp, J.; Zhao, B.; Ozaki, Y., Eds. Surface- and Tip-Enhanced Raman Scattering Spectroscopy; Springer, 2024.

(11) Ozaki, Y. Near-Infrared Spectroscopy—Its Versatility in Analytical Chemistry. Anal. Sci.2012, 28, 545–563. DOI: 10.2116/analsci.28.545

(12) Ozaki, Y.; Huck, C.; Tsuchikawa, S.; Engelsen, S. B., Eds. Near-Infrared Spectroscopy: Theory, Spectral Analysis, Instrumentation, and Applications; Springer, 2020.

(13) Czarnecki, M. A.; Morisawa, Y.; Futami, Y.; Ozaki, Y. Advances in Molecular Structure and Interaction Studies Using Near-Infrared Spectroscopy. Chem. Rev.2015, 115, 9707–9744. DOI: 10.1021/cr500013u

(14) Ozaki, Y.; Sato, H., Eds. Spectroscopic Techniques for Polymer Characterization; Wiley-VCH, 2021.

(15) Ozaki, Y.; Morisawa, Y.; Tanabe, I. ATR-Far-Ultraviolet Spectroscopy: A Challenge to New Chemistry. Chem. Soc. Rev.2024, 53, 1730–1768. DOI: 10.1039/d3cs00437f

(16) Wojcik, M.; Ozaki, Y. Spectroscopy and Computation of Hydrogen-Bonded Systems; Wiley-VCH, 2022.

(17) Ozaki, Y.; Beć, K. B.; Morisawa, Y.; Yamamoto, S.; Tanabe, I.; Huck, C. W.; Hofer, T. S. Advances, Challenges, and Perspectives of Quantum Chemical Approaches in Molecular Spectroscopy of the Condensed Phase. Chem. Soc. Rev.2021, 50, 10917–10954. DOI: 10.1039/D0CS01602K

(18) Jiang, J. H.; Berry, R. J.; Siesler, H. W.; Ozaki, Y. Wavelength Interval Selection in Multicomponent Spectral Analysis by Moving Window Partial Least-Squares Regression with Applications to Mid-Infrared and Near-Infrared Spectroscopic Data. Anal. Chem.2002, 74, 3555–3565. DOI: 10.1021/ac011177u

(19) Noda, I.; Ozaki, Y. Two-Dimensional Correlation Spectroscopy: Applications in Vibrational and Optical Spectroscopy; John Wiley & Sons: Hoboken, NJ, 2005.

About the Award Winner

Yukihiro Ozaki obtained his Ph.D. degree from Osaka University (1978). After he had spent for two years and a half at the National Research Council in Canada, he joined the Jikei University School of Medicine in Tokyo in 1981. In 1989 he moved to Kwansei Gakuin University, Japan. Since 1993, he has been a professor in the Department of Chemistry, School of Science and Technology, Kwansei Gakuin University. Ozaki retired in 2018, and currently, he is a professor emeritus and a university fellow, there, a guest professor of Kobe University, and a guest principal researcher of RIKEN.

Ozaki has made significant contributions to vibrational spectroscopy, including Raman, infrared, and near-infrared (NIR) spectroscopy. A pioneer in Raman spectroscopy, he advanced surface-enhanced Raman scattering (SERS) and its applications in nanomaterials, biology, and medical diagnostics. His NIR research spans fundamental studies, instrument development, spectral analysis, and applications. Recognized for his groundbreaking work, he has applied quantum chemical calculations and two-dimensional correlation spectroscopy across Raman, resonance Raman, far-ultraviolet (FUV), and far-infrared/terahertz spectroscopy.

Ozaki received many awards including the MIT Dasari Lecture Award (2011), and the Bomem-Michelson Award (2014). The Medal with Purple Ribbon from the Japanese Emperor (2018). Pittsburg Spectroscopy Award (2019). Charles Mann Award for Applied Raman Spectroscopy (2020). Karl Norris Award, (2021). The Medal of Ioannes Marcus Marci (2022). He is a fellow of the Society for Applied Spectroscopy and the Royal Society of Chemistry in UK (2019). He is a foreign member of the Polish Academy of Art and Sciences (2024). He has received the Ellis R. Lippincott Award for 2025.Michelson Award (2014). The Medal with Purple Ribbon from Japanese Emperor (2018). Pittsburg Spectroscopy Award (2019). Charles Mann Award for Applied Raman Spectroscopy (2020). Karl Norris Award, (2021). The Medal of Ioannes Marcus Marci (2022). He is a fellow of Society for Applied Spectroscopy and Royal Society of Chemistry. Poland (2019). He is a foreign member of Polish Academy of Art and Sciences (2024). He received Ellis R. Lippincott Award (2025).

About the Interviewer

Jerome Workman, Jr. serves on the Editorial Advisory Board of Spectroscopy and is the Executive Editor for LCGC and Spectroscopy. He is the co-host of the Analytically Speaking podcast and has published multiple reference text volumes, including the three-volume Academic Press Handbook of Organic Compounds, the five-volume The Concise Handbook of Analytical Spectroscopy, the 2nd edition of Practical Guide and Spectral Atlas for Interpretive Near-Infrared Spectroscopy, the 2nd edition of Chemometrics in Spectroscopy, and the 4th edition of The Handbook of Near-Infrared Analysis. Author contact: JWorkman@MJHlifesciences.com ●