Atomic Force Microscopy-Infrared Spectroscopy > Analysis of amyloid proteins and fibrils

Amyloid fibrils are composed of aggregated peptides or proteins in a fibrillary structure and possess a higher β-sheet content compared to their native counterparts. Traditional attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy provides only bulk analysis, limiting the discrimination between various aggregated species.

AFM-IR transcends this constraint. This nanospectroscopy approach enables the recording of IR spectra with an exceptional spatial resolution of ten nanometers, equivalent to the size of isolated fibrils.

In the AFM-IR images below, we can precisely differentiate protofibrils from amyloid fibrils during aggregation of the amyloid beta peptide.


J. Waeytens et al., Probing amyloid fibril secondary structures by infrared nanospectroscopy: experimental and theoretical considerations, Anayst 2021, 146, 132–45