Sequence-dependent force response during peeling of single-stranded DNA from graphite.
We have analyzed the statistical thermodynamics of peeling single-stranded DNA (ssDNA) from the surface of graphite. Using recently measured parameters, we represent ssDNA as a polymer chain strongly adsorbed to a frictionless substrate using the freely jointed chain, wormlike chain, and rotational isomeric state models. All three models predict steady peeling force under force control, in agreement with single-molecule experiments. We predict that, for finite-length chains, the force response has measurable spikes under displacement control. These force spikes carry information about the underlying sequence of ssDNA, which might thus be measurable with a sufficiently stiff loading system. For the freely jointed chain model, under force control, we have obtained several exact closed-form results and provide relations between the measured peel force and the underlying adhesion free energy.
Manohar
Suresh
S
Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Jagota
Anand
A
D000327:Adsorption; D004277:DNA, Single-Stranded / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics
D004277:DNA, Single-Stranded; D011108:Polymers; D006108:Graphite