Nanoscale Chemical Imaging of Amyloid Fibrils in Water Using Total-Internal-Reflection Tip-Enhanced Raman Spectroscopy
Language
EN
Article de revue
This item was published in
Journal of Physical Chemistry Letters. 2024-10-01, vol. 15, n° 40, p. 10190-10197
English Abstract
Total-internal-reflection tip-enhanced Raman spectroscopy (TIR-TERS) imaging of amyloid-β (Aβ1-42-L34T) fibrils is performed with nanoscale spatial resolution in water, using TERS tips fabricated by bipolar electrodeposition. ...Read more >
Total-internal-reflection tip-enhanced Raman spectroscopy (TIR-TERS) imaging of amyloid-β (Aβ1-42-L34T) fibrils is performed with nanoscale spatial resolution in water, using TERS tips fabricated by bipolar electrodeposition. Ideal experimental parameters are corroborated by both theoretical simulations and TIR-TERS measurements. TIR-TERS imaging reveals the predominant parallel β-sheet secondary structure of Aβ1-42-L34T fibrils, as well as the nanoscale spatial distribution of tyrosine, histidine and phenylalanine aromatic amino acids. Their proportion in TERS spectra can be qualitatively explained by the combined effect of their localization in the Aβ1-42-L34T fibril structure and their molecular orientation with respect to the excitation laser light polarization. Conclusions drawn from the TERS experiments in water corroborate and significantly enrich our previous study in ambient air, thus confirming that hydration has only a marginal impact on the structure of such amyloid fibrils. This first TIR-TERS study in liquid opens fascinating perspectives for future applications in biology.Read less <
English Keywords
Amyloid fibrils
Aqueous medium
Aromatic amino acid residues
Localized surface plasmon resonance
Tip-enhanced Raman imaging
Total internal reflection
ANR Project
Imagerie structurale et morphologique nanométrique d'agrégats bêta amyloïdes interagissant avec des membranes en milieu aqueux - ANR-20-CE29-0004