title: Direct observation of single DNA structural alterations at low forces with surface-enhanced Raman scattering.
abstract: DNA experiences numerous mechanical events, necessitating single-molecule force spectroscopy techniques to provide insight into DNA mechanics as a whole system. Inherent Brownian motion limits current force spectroscopy methods from observing possible bond level structural changes. We combine optical trapping and surface-enhanced Raman scattering to establish a direct relationship between DNA's extension and structure in the low force, entropic regime. A DNA molecule is trapped close to a surface-enhanced Raman scattering substrate to facilitate a detectable Raman signal. DNA Raman modes shift in response to applied force, indicating phosphodiester mechanical alterations. Molecular dynamic simulations confirm the local structural alterations and the Raman sensitive band identified experimentally. The combined Raman and force spectroscopy technique, to our knowledge, is a novel methodology that can be generalized to all single-molecule studies.
authors: ICFO - Institut de Ciències Fotòniques, Castelldefels (Barcelona), Spain.
authors: Satish
authors: S
authors: Rao
authors: Saurabh
authors: S
authors: Raj
authors: Benjamin
authors: B
authors: Cossins
authors: Monica
authors: M
authors: Marro
authors: Victor
authors: V
authors: Guallar
authors: Dmitri
authors: D
authors: Petrov
mesh_terms: D001696:Biomechanical Phenomena; D004277:DNA, Single-Stranded / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D052898:Optical Tweezers; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D014732:Vibration
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral