Experimental evidence of fragile-to-strong dynamic crossover in DNA hydration water

• DOI: 10.1063/1.2372491
• Publication Date: 2006-11-03T23:41:51Z
• Authors: S.-H. Chen; L. Liu; X. Chu; Y. Zhang; E. Fratini; P. Baglioni; A. Faraone; E. Mamontov
• Keywords: Quasielastic neutron scattering

We used high-resolution quasielastic neutron scattering spectroscopy to study the single-particle dynamics of water molecules on surface hydrated DNA samples. Both H2O and D2O samples were measured. The contribution from is subtracted out by taking difference signals between two measurement was made at a series temperatures 270 K down 185 K. Relaxing-Cage Model analyze spectra. This allowed us extract Q-independent average translational relaxation time as function temperature. observe clear evidence fragile-to-strong dynamic crossover (FSC) TL = 222+-2 plotting log vs. T. coincidence transition temperature Tc DNA, signaling onset anharmonic molecular motion, FSC hydration suggests that change mobility across drives in DNA.