title: Optical measurement of torsional spring modulus of a double-stranded DNA using half-coated nanoparticles.
abstract: A technique of detecting the rolling and spinning of half-coated nanoparticles using interference ring patterns of the fluorescence has been applied to the measurement of torsional spring modulus of a double-stranded DNA. Using the unique ability to measure nanoparticle rotations in multiple degrees of freedom, we were able to determine the spinning of a nanoparticle tethered on the DNA and thereby the twisting of the DNA in real time. The detailed knowledge of the spinning as well as rolling behaviors of half-coated nanoparticles provides information about torsional elastic properties of the DNA under investigation.
authors.affiliation: Dept. of Electr. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA.
authors.forename: Jaehyuck
authors.initials: J
authors.lastname: Choi
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Heller
authors.forename: Y-H
authors.initials: YH
authors.lastname: Lo