2023/03/08 by Jiajun Du, Du, Jiajun, Xuecheng Tao +5
Biochemistry, Genetics and Molecular Biology · Chemistry · Materials Science · #Atomic physics #Chemical Physics (physics.chem-ph) #Chemistry #Electron paramagnetic resonance #Excitation #FOS: Physical sciences #Gold and Silver Nanoparticles Synthesis and Applications #Materials science #Microscopy #Molecular physics #Nuclear magnetic resonance #Optics #Physics #Protein Interaction Studies and Fluorescence Analysis #Raman scattering #Raman spectroscopy #Resonance (particle physics) #Spectroscopy Techniques in Biomedical and Chemical Research
paper · pdf · doi:10.48550/arxiv.2303.04922
openalex publication_date 2023/03/08 · openalex created_date 2023/03/12 · openalex updated_date 2026/08/06
Recently developed electronic pre-resonance stimulated Raman scattering (epr-SRS) microscopy, in which the Raman signal of a dye is significantly boosted by setting the incident laser frequency near the electronic excitation energy, has pushed the sensitivity of SRS microscopy close to that offered by confocal fluorescence microscopy. Prominently, the maintained narrow line-width of epr-SRS also offers high multiplexity that breaks the "color barrier" in optical microscopy. However, detailed understandings of the fundamental mechanism in these epr-SRS dyes still remain elusive. Here, we combine experiments with theoretical modeling to investigate the structure-signal relationship, aiming to facilitate the design of new probes and expanding epr-SRS palettes. Our ab initio approach employing the displaced harmonic oscillator (DHO) model provides a consistent agreement between simulated and experimental SRS intensities of various triple-bond bearing epr-SRS probes with distinct scaffolds. We further review two popular approximate expressions for epr-SRS, namely the short-time and Albrecht A-term equations, and compare them to the DHO model. Overall, the theory allows us to illustrate how the observed intensity differences between molecular scaffolds stem from the coupling strength between the electronic excitation and the targeted vibrational mode, leading to a general design strategy for highly sensitive next-generation vibrational imaging probes.