title: Magnetic force probe for nanoscale biomolecules.
abstract: We present a new technique to measure the mechanical properties of small biomolecules. This technique uses long range repulsive colloidal forces together with magnetic attraction as a force probing tool. The biomolecules are grafted between superparamagnetic particles, which are regularly spaced within long chains maintained by an external magnetic field. Varying the magnetic field results in compression or extension of the molecules between the particles. In order to demonstrate this technique we use, as a size controlled model molecule, a short double stranded DNA (151 base pairs) for which the force-extension law is determined and found in agreement with existing predictions.
authors.affiliation: Laboratoire Colloïdes et Matériaux Divisés, UMR 7612, ESPCI, 10 rue Vauquelin, 75005 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Koenig
authors.forename: P
authors.initials: P
authors.lastname: Hébraud
authors.forename: C
authors.initials: C
authors.lastname: Gosse
authors.forename: R
authors.initials: R
authors.lastname: Dreyfus
authors.forename: J
authors.initials: J
authors.lastname: Baudry
authors.forename: E
authors.initials: E
authors.lastname: Bertrand
authors.forename: J
authors.initials: J
authors.lastname: Bibette
mesh_terms: D001704:Biopolymers / Q000032:analysis* / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D008280:Magnetics; D049329:Nanostructures / Q000032:analysis* / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D001704:Biopolymers; D004247:DNA