Dipeptide Nanostructure Assembly and Dynamics <i>via in Situ</i> Liquid-Phase Electron Microscopy

Abstract

In this paper, we report the <i>in situ</i> growth of FF nanotubes examined <i>via</i> liquid-cell transmission electron microscopy (LCTEM). This direct, high spatial, and temporal resolution imaging approach allowed us to observe the growth of peptide-based nanofibrillar structures through directional elongation. Furthermore, the radial growth profile of FF nanotubes through the addition of monomers perpendicular to the tube axis has been observed in real-time with sufficient resolution to directly observe the increase in diameter. Our study demonstrates that the kinetics, dynamics, structure formation, and assembly mechanism of these supramolecular assemblies can be directly monitored using LCTEM. The performance of the peptides and the assemblies they form can be verified and evaluated using <i>post-mortem</i> techniques including time-of-flight secondary ion mass spectrometry (ToF-SIMS).