Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
The three-dimensional spatial distribution of molecules at soft matter interfaces is crucial for processes ranging from membrane biophysics to atmospheric chemistry. While several techniques can access surface composition, obtaining information on the depth distribution is challenging. We develop a noninvasive, polarization-resolved, surface-specific sum-frequency generation spectroscopy providing quantitative depth information. We demonstrate the technique on formic acid molecules at the air-water interface. With increasing molar fraction from 2.5% to 10%, the formic acid molecules shift, on average, ∼0.9 Å into the bulk. The consistency with the simulation data manifests that the technique allows for probing the Ångstrom-scale depth profile.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.128.226001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sub-1 cm-1 high-resolution broadband sum-frequency generation vibrational spectroscopy (HR-BB-SFG-VS) with significantly improved sensitivity and signal-to-noise ratio (SNR).
J Chem Phys
September 2025
Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang Province 310027, China.
Sum-frequency generation vibrational spectroscopy (SFG-VS) has been well-established as a unique spectroscopic probe to interrogate the structure, interaction, and dynamics of molecular interfaces, with sub-monolayer sensitivity and broad applications. Sub-1 cm-1 High-Resolution Broadband SFG-VS (HR-BB-SFG-VS) has shown advantages with high spectral resolution and accurate spectral line shape. However, due to the lower peak intensity for the long picosecond pulse used in achieving sub-wavenumber resolution in the HR-BB-SFG-VS measurement, only molecular interfaces with relatively strong signal have been studied.
View Article and Find Full Text PDFMode-Specific Coherent Interference of Vibrational Sum-Frequency Generation Imaging: An Approach to Differentiate Lung Tumors through Collagen Interfibrillar Distances.
J Am Chem Soc
September 2025
Department of Chemistry and Biochemistry, UC San Diego, La Jolla, California 92093, United States.
Chemical imaging holds great promise for chemical, materials, and biological applications. However, its contrast often relies on subtle spectral differences arising from molecular-level changes. Here, we introduce label-free chemical imaging based on bond-specific coherent interference, which is highly sensitive to nanoscopic structural variations in collagen fibers.
View Article and Find Full Text PDFTowards Floquet Chern insulators of light.
Nat Nanotechnol
September 2025
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA.
Topological photonics explores photonic systems that exhibit robustness against defects and disorder, enabled by protection from underlying topological phases. These phases are typically realized in linear optical systems and characterized by their intrinsic photonic band structures. Here we experimentally study Floquet Chern insulators in periodically driven nonlinear photonic crystals, where the topological phase is controlled by the polarization and the frequency of the driving field.
View Article and Find Full Text PDFEvaluating the Structural Response of Amphiphilic Monolayers to Environmental Stimuli.
Langmuir
September 2025
Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235-1604, United States.
Amphiphilic monolayers composed of end groups with distinct polar and nonpolar functional groups offer rapid and reversible interfacial adaptation in response to environmental stimuli such as a change in interfacial medium polarity. We have synthesized and characterized a suite of monolayers with functional groups of competing polarity designed to reconfigure their interfacial chemical composition in response to solvent polarity. In these films, the end group is designed to be able to reorient and expose the functional groups that minimize the interfacial free energy between the film and the environment.
View Article and Find Full Text PDFUniaxial order parameters associated with surface SFG spectra. I. Distributions with cylindrical symmetry.
J Chem Phys
September 2025
Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada.
Order parameters provide a useful qualitative and quantitative description of the distribution of molecules in ordered materials as they are independent of the shape of the orientation distribution. For samples that exhibit uniaxial ordering with no twist preference, extracting ⟨P2⟩ from polarized IR absorption data is common and obtaining ⟨P2⟩ and ⟨P4⟩ from Raman data has also been well-described. However, such an approach is not routine in the analysis of surface sum-frequency generation (SFG) spectra.
View Article and Find Full Text PDF