The recent coupling of infrared spectroscopy with atomic force microscopy (AFM-IR) overcomes the weak spatial resolution of the usual infrared microscopy and achieve a resolution around 10 nm. The AFM-IR allows recording spectrum and absorption mapping of many sample (proteins, cells or even tissue). This new technique will be described and results on amyloids will be presented.

In Alzheimer’s disease, we observe amyloid plaques in the brain that are made of aggregated forms of amyloid b peptide. We study the aggregation of the peptide alone and follow changes in the structure of isolated amyloid fibrils. Some AFM-IR results were also obtained on neurons and brain sections. The AFM-IR provides molecular information at nanoscale resolution and can be applied on various samples. It will help to better understand diseases related to protein structural changes, especially in the field of protein aggregation.

Jehan Waeytens, post-doc Université libre de Bruxelles, obtained a BSc in chemistry at Institut Paul Lambin in 2011. After that, he worked for five years at ExxonMobil in the Advanced Characterization Group (mainly on SEM, FTIR and NMR). Jehan also obtained a mMaster’s in chemistry at ULB in 2016 with a master thesis on nanospectroscopy for polymer, and then obtained his PhD in 2022 on the infrared nanospectroscopie on amyloid beta peptide. Currently, he is a post-doc, continuing his research on amyloid beta but with biofunctionalized AFM tip. The focus of the lab is the biophysical characterization of protein (soluble and membrane) and with a strong focus and experience on infrared spectroscopy.