Detachment of a single polyelectrolyte chain adsorbed on a charged surface

We study both experimentally, with an atomic force microscope (AFM), and theoretically, using scaling arguments, the stretching of a single polyelectrolyte chain adsorbed at a planar charged surface. The main result is that the force needed to pull a monomer of the chain at a distance z from the surface reaches a plateau at distances larger than the Debye screening length of the solution.