Nanometer-Scale Force Profiles of Short Single- and Double-Stranded DNA Molecules on a Gold Surface Measured Using a Surface Forces Apparatus.

ABSTRACT: Using a surface forces apparatus (SFA), we have studied the nanomechanical behavior of short single-stranded and partially and fully double-stranded DNA molecules attached via one end to a self-assembled monolayer on a gold surface. Our results confirm the previously proposed "mushroom-like" polymer structure for surface-attached, single-stranded DNA at low packing density and a "brush-like" structure for the same construct at higher density. At low density we observe a transition to "rigid rod" behavior upon addition of DNA complementary to the surface-attached single strand as the fraction of molecules that are double-stranded increases, with a concomitant increase in the SFA-observed thickness of the monolayer and the characteristic length of the observed repulsive forces. At higher den

SUBMITTER: Kang D 

PROVIDER: S-EPMC8968159 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature