Molecular hierarchic conformations of peptide fibrils with polar growth mechanism by dynamically mapping ionic charge carriers

Harness of surface charge has been widely found in materials functionalization, life-related bioactivities and chemical reactions. Specifically, ionic charge carriers (ICC), it plays a key role in bio-nano coupling interfaces such as protein corona phenomenon. However, in thermodynamics and kinetic conditions, understanding the roles of ICC at bio-nano interfaces affecting biomolecular conformations, systematic energy landscapes, and on-demand bio-nano-functions is still a challenge task, lacking direct visualization of ICC and dynamically revealing its specific effect on surface characteristics of bio-nano interactions. We utilized high-speed ion conductance microscopy combined with high-resolution AFM techniques and peptide self-assembly on mica as a good model to explore significant roles of ICC in 1) differing peptide hierarchic conformations including amorphous and ordered phases in dynamics, 2) unveiling asymmetrical polar growth mechanism and 3) bias-modulated assembly-disassembly reversible process at peptide-mica interfaces. This work sheds light on quantifying the significant role of ICC at bio-nano hybrid soft interfaces.