Hexafluoro 2 propanol treated aβ42

β-barrel and amyloid fibril formation of Aβ42 were confirmed using TEM. For this, hexafluoro-2-propanol treated Aβ42 (Anaspec) was dissolved in 10 μL of 1% NH₄OH and then Milli-Q water was added to obtain a stock Aβ42 concentration of 100 μM. The peptide solution was incubated up to 48 h at 37 °C. At specific time points of incubation (0 to 48 h of incubation), 5 μL of peptide-containing solution was pipetted onto a glow discharged (15 s) copper grid (400 mesh; ProSciTech), followed by 1 min of adsorption. Excess sample was then drawn off using filter paper and the grid was washed by Milli-Q water with the excess drawn off. The grid was stained with a drop of 1% uranyl acetate for 30 s, then the excess stain was drawn off and the grid was air dried. Imaging was performed by a Hitachi HT770 transmission electron microscope operated at a voltage of 80 kV.

Ultrasmall MoS₂ QDs and the amyloid fibril formation of Aβ₄₂ were imaged with TEM. Hexafluoro-2-propanol treated Aβ₄₂ (AnaSpec) was dissolved in 10 μL of 0.1% NH₄OH and then Milli-Q water was added to obtain a stock of 100 μM Aβ₄₂. TEM images were acquired with a scanning transmission electron microscope (FEI Tecnai F20 operated at 200 kV) equipped with energy dispersive spectroscopy detectors. 10 μL of samples were placed onto glow-discharged, formvar/carbon-coated copper grids (400 mesh, ProSciTech). After 1 min incubation, the grids were dried on Whatman filter paper followed by a single wash with MilliQ H₂O (5 μL), then negatively stained with 5 μL of uranyl acetate (UA, 1%). The grids were further dried on Whatman filter paper prior to insertion into specimen holders.