Researchers have achieved a remarkable one-hundredfold increase in the measurement rate of Raman spectroscopy, a popular technique used to capture the “vibrational fingerprint” of molecules for identification purposes. This enhancement addresses a major bottleneck in measurement speed, paving the way for progress in various fields that depend on molecular and cellular identification, including biomedical diagnostics and material analysis. The results were published in the journal Ultrafast Science.
A team of researchers, including Takuma Nakamura, Kazuki Hashimoto, and Takuro Ideguchi from the Institute for Photon Science and Technology at the University of Tokyo, has successfully increased the measurement rate of Raman spectroscopy by 100 times. This technique is crucial for identifying molecules by measuring their unique “vibrational fingerprints.” Given that measurement speed has been a significant limitation, this advancement is expected to benefit many fields such as biomedical diagnostics and material analysis. Their research findings were published in the journal Ultrafast Science.
Identifying different molecular types and cells is essential in both fundamental and applied sciences. Raman spectroscopy is a popular technique used for this purpose. When a laser beam hits molecules, the light interacts with the vibrations and rotations of molecular bonds, causing the frequency of the scattered light to shift. The resulting scattering spectra represent a molecule’s distinctive “vibrational fingerprint.”
According to Ideguchi, the principal investigator of the study, “Measurement is the foundation of science, and we aim to achieve the highest performance in our measurement systems. Our focus is on advancing the frontiers of optical measurements.”
Raman spectroscopy has seen numerous attempts for enhancement, largely due to its measurement rate being a limiting factor. This has resulted in its inability to keep pace with rapid changes in some chemical and physical reactions. To tackle this issue, the team decided to construct a new measurement system from the ground up.
Ideguchi mentions, “I had been pondering this idea for over ten years without the chance to initiate the project until we developed an optimal laser system a few years back, which finally allowed progress to be made.”
Utilizing their knowledge in optics and photonics, the researchers effectively combined three components: coherent Raman spectroscopy—which generates stronger signals than conventional spontaneous Raman spectroscopy—a specially designed ultrashort pulse laser, and time-stretch technology using optical fibers. This combination led to a remarkable measurement rate of 50MSpectra/s (megaspectra per second), marking a hundredfold increase from the previous maximum of 50kSpectra/s (kilospectra per second). Ideguchi highlights the extensive potential of this improvement.
He states, “Our goal is to incorporate our spectrometer into microscopy, allowing for the capture of 2D or 3D images using Raman scattering spectra. We also see possibilities for applications in flow cytometry by merging this technology with microfluidics. These systems will facilitate high-throughput, label-free chemical imaging and spectroscopy of biomolecules within cells or tissues.”
