title: High speed indentation measures by FV, QI and QNM introduce a new understanding of bionanomechanical experiments.
abstract: Structural and mechanical mapping at the nanoscale by novel high-speed multiparametric Quantitative Imaging (QI) and PeakForce Quantitative Nanomechanical Mapping (PF-QNM) AFM modes was compared to the classical Force Volume (FV) mapping for the case of living Pseudomonas aeruginosa bacterial cells. QI and PF-QNM modes give results consistent with FV for the whole cells in terms of morphology and elastic modulus, while providing higher resolution and shorter acquisition time. As an important complement, the influence of scanning parameters on elastic modulus values was explored for small 0.2(2)μm(2) central area on top of cells. The modulus decreases with the indentation depth due to the effect of the hard cell wall, while it increases vs. tip oscillation frequency, displaying viscoelastic behaviour of the living bacterial cells. The ability of different AFM modes to follow correctly the bacteria viscoelastic behaviour at high oscillation frequency was tested.
authors.affiliation: ITAV, Université de Toulouse, CNRS, UPS, France; LAAS-CNRS, Université de Toulouse, CNRS, UPS, France.
authors.forename: G
authors.initials: G
authors.lastname: Smolyakov
authors.affiliation: LAAS-CNRS, Université de Toulouse, CNRS, UPS, France; CNRS, SRSMC (Structure et Réactivité des Systèmes Moléculaires Complexes), UMR 7565, Nancy, France; Université de Lorraine, SRSMC, UMR 7565, Faculté de Pharmacie, Nancy, France.
authors.forename: C
authors.initials: C
authors.lastname: Formosa-Dague
authors.affiliation: ITAV, Université de Toulouse, CNRS, UPS, France.
authors.forename: C
authors.initials: C
authors.lastname: Severac
authors.affiliation: CNRS, SRSMC (Structure et Réactivité des Systèmes Moléculaires Complexes), UMR 7565, Nancy, France; Université de Lorraine, SRSMC, UMR 7565, Faculté de Pharmacie, Nancy, France; ABC Platform(®), Nancy, France.
authors.forename: R E
authors.initials: RE
authors.lastname: Duval
authors.affiliation: ITAV, Université de Toulouse, CNRS, UPS, France; LAAS-CNRS, Université de Toulouse, CNRS, UPS, France. Electronic address: edague@laas.fr.
authors.forename: E
authors.initials: E
authors.lastname: Dague
keywords: Atomic force microscopy; Elastic modulus; Force volume; Living bacterial cells; PeakForce quantitative nanomechanical mapping; Quantitative imaging