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Author Spotlight: Unveiling the Structural and Dynamic Aspects of Glycan Molecular Recognition
Published on: May 17, 2024
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Using solution state NMR spectroscopy to probe NMR invisible gelators.
Matthew Wallace1, Jonathan A Iggo, Dave J Adams
1Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK. d.j.adams@liverpool.ac.uk.
Soft Matter
|August 28, 2015
Summary
This study introduces a novel solution-state Nuclear Magnetic Resonance (NMR) method to track the complete self-assembly of supramolecular hydrogels. The technique monitors changes in aggregate properties, enabling a deeper understanding of hydrogel formation dynamics.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Biophysical Chemistry
Background:
- Supramolecular hydrogels self-assemble from gelator molecules triggered by external stimuli.
- Understanding hydrogel self-assembly is crucial for designing advanced materials.
- Conventional Nuclear Magnetic Resonance (NMR) spectroscopy is limited in tracking the full self-assembly process due to low molecular mobility in aggregates.
Purpose of the Study:
- To develop and demonstrate a new solution-state NMR method for observing the entire self-assembly process of supramolecular hydrogels.
- To investigate the multi-stage assembly of a dipeptide gelator triggered by pH reduction.
- To characterize the evolving properties of supramolecular aggregates during hydrogel formation.
Main Methods:
- Utilized solution-state NMR spectroscopy to monitor supramolecular hydrogel self-assembly.
- Employed residual quadrupolar couplings (RQCs) of (14)NH4(+) and isopropanol-d8 as molecular probes.
- Measured NMR relaxation rates of (23)Na(+) to assess aggregate properties.
- In situ pH measurement by NMR spectroscopy was performed.
Main Results:
- Successfully followed the complete multi-stage self-assembly of a dipeptide-based hydrogel.
- Observed changes in aggregate charge, hydrophobicity, and arrangement during pH-triggered assembly.
- Demonstrated that initially negatively charged fibrils become hydrophobic as pH decreases, leading to hydrogel contraction.
- Validated the accuracy and convenience of in situ NMR for pH monitoring.
Conclusions:
- The developed NMR method enables comprehensive monitoring of supramolecular hydrogel self-assembly.
- The study elucidates the dynamic changes in aggregate characteristics during pH-induced gelation.
- This approach provides valuable insights for the rational design and application of supramolecular hydrogels.
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