Tip-enhanced Raman spectroscopy of A?(1-42) fibrils

Using tip-enhanced Raman spectroscopy (TERS) imaging with a lateral optical resolution of ~16 nm, the heterogeneity A?(1-42) fibrils implicated in Alzheimer’s disease is investigated. The amount and spatial distribution TERS bands assigned to aromatic amino acid residues (histidine, tyrosine phenylalanine) parallel ?-sheet random coil secondary structures suggest that both surface core are probed, confirm twisted nature reveal presence several disordered fibril regions different hydrophilicity. This study completes bears out literature data on amyloid fibrils.