To examine if the ability to penetrate the membrane interior affects the Aβ (mis)folding trajectory, we monitored Aβmembrane interactions in different membrane architectures using SEIRA spectroscopy. In order to prevent incorporation into the membrane, a tethered monolayer lipid membrane (tMLM) was assembled on a dense lipid tether-SAM; instead to enable incorporation a tethered bilayer lipid membrane (tBLM) with free-floating bilayer patches was used (Figure ). We have used this strategy in earlier work on the spontaneous and transmembrane potential-induced incorporation of the model peptide alamethicin, and were able to successfully control between interfacial adsorption and transmembrane insertion as observed via distinct horizontal or vertical orientations of the αhelical peptide. Both systems were constructed using a 9:1-POPC:POPG mixture of lipids as negative surface charge was reported to promote misfolding at interfaces; in the SI we further present experimental data with positively charged and neutral lipids (SI Section 3).