The objective of this work is to determine the operating range of proteins with high selectivity for lanthanides (III) or Am(III) under acid and radiation stress. The effects will be quantified by analyzing how the following three properties evolve under stress: protein surface density, changes in their structural configuration upon interaction with f-block elements, and their degradation. To this end, the candidate will prepare two types of model systems. The first type, flat silicon and germanium substrates, will be used for ex situ (pH and irradiation) and in situ (pH) surface analyses, X-ray and neutron reflectivity measurements in the laboratory and on large-scale instruments (Institut Laue Langevin), atomic force microscopy (AFM), and attenuated total reflection infrared spectroscopy. Based on these analyses, the surface density of proteins and their in situ behavior in the presence of f-block elements will be determined. The second type of substrate—inorganic oxide powders functionalized with proteins—will be used to determine any potential degradation of the proteins in solution under irradiation by analyzing the solution via mass spectrometry and the solid phase via small-angle X-ray scattering.