title: Double-layer mediated electromechanical response of amyloid fibrils in liquid environment.
abstract: Harnessing electrical bias-induced mechanical motion on the nanometer and molecular scale is a critical step toward understanding the fundamental mechanisms of redox processes and implementation of molecular electromechanical machines. Probing these phenomena in biomolecular systems requires electromechanical measurements be performed in liquid environments. Here we demonstrate the use of band excitation piezoresponse force microscopy for probing electromechanical coupling in amyloid fibrils. The approaches for separating the elastic and electromechanical contributions based on functional fits and multivariate statistical analysis are presented. We demonstrate that in the bulk of the fibril the electromechanical response is dominated by double-layer effects (consistent with shear piezoelectricity of biomolecules), while a number of electromechanically active hot spots possibly related to structural defects are observed.
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: Nikiforov
authors.forename: G L
authors.initials: GL
authors.lastname: Thompson
authors.forename: V V
authors.initials: VV
authors.lastname: Reukov
authors.forename: S
authors.initials: S
authors.lastname: Jesse
authors.forename: S
authors.initials: S
authors.lastname: Guo
authors.forename: B J
authors.initials: BJ
authors.lastname: Rodriguez
authors.forename: K
authors.initials: K
authors.lastname: Seal
authors.forename: A A
authors.initials: AA
authors.lastname: Vertegel
authors.forename: S V
authors.initials: SV
authors.lastname: Kalinin
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000682:Amyloid / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D004560:Electricity; D055595:Mechanical Phenomena; D008853:Microscopy; D015999:Multivariate Analysis; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D000682:Amyloid; D014867:Water; C011934:mica