After the incubation of the Au(111) sc /PEG-C9t sample in the spike protein solution, elevated globular features were observed in AFM topography that were absent before (figure ). The features' shapes are dominated by the AFM tip shape, and they protrude approx. 3 nm to 4 nm from the receptor layer from their line profiles (figure ). The line profile on the uniform receptor layer (figure ) illustrates height variations of 1 nm similar to the phase seperated Au(111) sc /PEG-C9t (figure ). The comparison of the AFM topographies before and after protein incubation shows that the appearance of the elevated features resulted from the protein incubation. Hence, the features are assigned S proteins and further evidence for this assignment is provided by the nano-IR results. Nano-IR point spectroscopy on protein features was used to study their chemistry and nature. Point spectra on several features and on random positions next to them on the receptor layer were recorded and averaged (figure ). In the range from 1000 cm -1